Group Title: Myology of the Limpkin
Title: Myology of the limpkin
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Title: Myology of the limpkin
Alternate Title: Limpkin
Physical Description: iv, 339, 1 leaves. : illus. ; 28 cm.
Language: English
Creator: Allen, Ted T., 1932-
Publication Date: 1962
Copyright Date: 1962
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Subject: Biology thesis Ph. D
Dissertations, Academic -- Biology -- UF
Genre: bibliography   ( marcgt )
non-fiction   ( marcgt )
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Thesis: Thesis -- University of Florida.
Bibliography: Bibliography: leaves 329-332.
General Note: Manuscript copy.
General Note: Vita.
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Bibliographic ID: UF00098228
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: alephbibnum - 000577088
oclc - 13913332
notis - ADA4779

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MYOLOGY OF THE LIMPKIN














By
TED T. ALLEN


A DISSERTATION PRESENTED TO THE GRADUATE COUNCIL OF
THE UNIVERSITY OF FLORIDA
IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE
DEGREE OF DOCTOR OF PHILOSOPHY












UNIVERSITY OF FLORIDA

June, 1962














ACKNOWLEDGMENTS


I am sincerely and deeply grateful for the generous

help and skillful guidance of my chairman, Dr. Pierce Brod-

korb, and for the use of his reference materials and skeleton

collection.

I also thank the other members of my committee, Drs.

E. C. Bovee, E. S. Ford, J. N. Layne, and J. R. Redmond,

for their help and constructive suggestions.

Grateful acknowledgment is also due the Florida State

Game and Freshwater Fish Commission for the issuance of a

special permit for collection of a small number of limpkins.

Dr. O. L. Austin, Jr., Mr. Anthony Austin, and Mr. Earl May

contributed needed specimens. Dr. Glen E. Woolfenden and

Mr. Robert McFarlane contributed specimens and also, along

with Dr. Dale E. Birkenholz, gave various other forms of

valuable assistance. I am indeed grateful for their help.

One summer of work was completely financed by a Fellow-

ship for Teaching Assistants from the National Science

Foundation, and partial coverage for another summer was pro-

vided by a fellowship from the College of Arts and Sciences

of the University of Florida. The monetary assistance was

invaluable, since it greatly reduced the time required to

complete the dissertation.














TABLE OF CONTENTS


Page
ACKNOWLEDGMENTS . . . . . . . . . .. ii

LIST OF ILLUSTPATIONS . . . . . . . . iv

INTRODUCTION ................ . .. 1

DESCRIPTIVE MYOLOGY . . . . . . . . . 4

Muscles of the Skull . . . . . . . 5
Muscles of the Hyoid . . . . . . .. 54
Muscles of the Orbit. . . . . . . a88
Muscles of the Wing . . . . . . .. .98
Muscles of the Tail . . . . . . . 197
Muscles of the Leg . . . . . . .. 217

DISCUSSION . . . . . . . . .. . . 308

CONCLUSIONS . . . . . . . . .. . . 323

SUMMARY. . . . . . . . . . . . 327

LITERATURE CITED ............... . 329

BIOGRAPHICAL SKETCH . . . . . . . ... .339














LIST OF ILLUSTRATIONS


Figure Page

1. Lateral and posterior views of the skull of the
limpkin, showing attachments of the muscles in
the occipital region . . . . . ... 333

2. Lateral views of the skulls of certain birds,
showing the position of the cranial attachment
(anterior origin) of M. Dermo-temporalis . . 334

3. Lateral view of the skull of the limpkin,
showing attachments of the muscles of the jaws
and of the orbit . . . . . . . .. 335

4. Ventral view of the skull of the limpkin, show-
ing attachments of muscles . . . . . 336

5. Medial view of the left eyeball of the limpkin,
showing the muscles of the eye and their attach-
ments . . . . . . . . ... . 337

6. Palmar and anconal views of the left humerus,
showing attachments of certain muscles of the
wing . . . . . . . . ... . . 338













INTRODUCTION


The limpkin, Aramus guarauna (Linnaeus), is the sole

living member of the avian family Aramidae of the order

Gruiformes. It occurs in southeastern Georgia, Florida, the

Greater Antilles, and the Neotropical mainland from Mexico to

Argentina (American Ornithologists' Union, 1957). The spe-

cies is known from a pre-Columbian site in Venezuela (Wet-

more, 1935) and from four localities in the Upper Pleisto-

cene of Florida (Wetmore, 1931; Brodkorb, 1956; Woolfenden,

1959). Other members of the family occur in Tertiary depos-

its of the Great Plains, Aramus sp. from the Lower Pliocene

of Nebraska (Wetmore, 1928), Aramornis longurio Wetmore

(1926b)from the Middle Miocene of Nebraska, Gnotornis

aramiellus Wetmore (1942) from the Upper Oligocene of South

Dakota, and Badistornis aramus Wetmore (1940) from the Mid-

dle Oligocene of South Dakota.

The living limpkin is adapted to a rather unique diet.

This consists almost exclusively of large snails of the

genus Pomacea, formerly known as Ampullaria, with occasional

other gastropod and pelecypod mollusks (Wetmore, 1926a: Cot-

tam, 1936). The bird usually takes the snail to a regular

feeding station and with its long, specialized bill pecks

through the operculum, extracts, and swallows the soft body

of the mollusk.






2

The bird occurs primarily in grassy marshes and wooded

swamps (Bent, 1926; Wetmore, 1926a;Nicholson, 1928). Where

bushes or trees are available it perches and nests in them,

often at some height from the ground.

Both the feeding and perching habits of the limpkin are

thus quite distinctive and differ from the usual condition

of its ordinal allies, the rails and cranes. Adaptations to

a specialized way of life would be expected to obscure re-

semblances to its nearest relatives and may account for some

of the disagreement over the systematic position of the

Aramidae.

The subordinal position of the limpkin has not been es-

tablished with certainty, although all workers have referred

it to one of two suborders, the Grues or the Ralli. Some of

the difficulties involved may be seen in a brief review of

the opinions of other workers on the systematic position of

the Aramidae. Audubon (1839) thought Aramus to be allied to

the rails on the basis of the viscera. Nitzsch (1867) found

that the pterylosis resembles that of Grus and Psophia and

no other bird; nevertheless, he placed it with the rails be-

cause of peculiarities of the feathers themselves. Garrod

(1876) considered Aramus as being closer to Grus, on the ba-

sis of several anatomical features, especially of the skull,

sternum, and some aspects of the thigh musculature. Shufeldt

(1894) placed it with the cranes but considered the species

a perfect link between cranes and typical rails. Clay (1950)

found the aramid Mallophaga to be rail-like and strongly






3

different from the type found in cranes. On the basis of

the electrophoretic profiles of egg-white proteins, Sibley

(1960) thought Aramus to be closer to the rails, and he men-

tioned the large hallux, feathered head, and color of the

downy young as also being rail-like.

From a broader view, these opinions indicate that the

Aramidae are definitely related to both the Gruidae and the

Rallidae. A major purpose of this paper is to investigate

affinities of the three families through study of their com-

parative myology. Fisher (1955) remarked that detailed ana-

tomical work should solve the question of affinities.














DESCRIPTIVE MYOLOGY


During the course of this study, six limpkins were

available for dissection. Two were dissected in detail and

critical points were checked in the others. To represent

both wading and swimming types of Rallidae, two specimens of

the clapper rail, Rallus longirostris Boddaert, and two of

the coot, Fulica americana Gmelin, were dissected. Some

features were also examined on a specimen of the purple gal-

linule, Porphyrula martinica (Linnaeus). A specimen of the

crowned crane, Balearica pavonina (Linnaeus), was dissected

as representing a generalized gruid, and comparisons were

made with Fisher and Goodman's (1955) description of the more

specialized whooping crane, Grus americana (Linnaeus), and

Berger's (1956a)study of the appendicular myology of the

sandhill crane, Grus canadensis (Linnaeus). All dissections

follow the basic plan of the excellent work by Fisher and

Goodman (1955), whose descriptions are quite adequate as a

guide to dissection of the species used in this study. With

very few exceptions, each muscle discussed by those authors

is found in each of the other species, and only a few are

present that are not discussed by them.

In the descriptions of individual muscles comparisons

are made on the basis of their proportions, as if all spe-

cies studied were of the same size. Attention is called to

4








differences in general configuration, points of attachment,

and function, at the specific, generic, or family levels, in

an effort to determine the relationship of the limpkin to

the cranes and rails.


Muscles of the Skull


1. M. dermo-temporalis

Elongate and sheet-like dermo-osseous muscle. Covers

lateral surface of full length of neck. Attaches to cranium,

to furculum, to M. tracheohyoideus, and to skin of neck.

Lies just beneath skin and deep to lateral edge of

sheet of M. constrictor colli in anterior half of neck. Lat-

eral to dermal fasciculi of Mm. intertransversarii. Anterior

end superficial to posterodorsal portion of M. depressor

mandibulae, ventrolateral edge of cephalic part of M. cucul-

laris, anterodorsal portion of M. rectus capitis lateralis,

side of fourth and fifth fasciculi of M. rectus capitis

superior, and dorsal tip of hyoid cartilage.

Origin. In two parts, both fleshy, at opposite ends of

muscle. Anterior origin from posterolateral edge of skull

bordering posterior edge of temporal fossa and extending to

base of opisthotic process, in a narrow line 8 mm long, just

posteroventral to origins of deep slip of M. adductor

mandibulae externus superficialis and rostral slip of M. ad-

ductor mandibulae externus profundus. Anterior origin sepa-

rates origins of latter two muscles from both anterior edge

of origin of M. depressor mandibulae and anteroventral edge

of origin of M. cucullaris, cephalic part.








Posterior origin is in common with M. tracheohyoideus

as result of fusion of the two muscles. Common sheet origi-

nates from narrow line along anterolateral edge of ventral

three-fourths of furculum, extending to mid-ventral line.

From this origin the sheet runs anterodorsad onto the neck.

Insertion. By connective tissue, onto skin of neck, by

all but anterior 10-18 mm of length of muscle. Fuses medi-

ally with M. tracheohyoideus at ninth or tenth cervical ver-

tebra to form common sheet. Posterior to fusion the common

sheet covers neck, except in narrow area along middorsal and

mid-ventral lines. A few short bundles, arising from furcu-

lum, leave dorsomedial edge of muscle near its posterior end

and insert on skin of neck near middorsal line.

Action. Tenses skin of neck.

Comparisons. In the Gruidae the muscle undergoes change.

In Balearica it is similar to the condition just described in

Aramus, but the belly is much thinner. Grus is apparently

unique in lacking the furcular origin and in having a very

short belly. The condition of the muscle in Grus might well

be re-examined, since the three specimens used by Fisher and

Goodman were skinned before dissection, and also because the

posterior regions are very thin and difficult to see.

In the Rallidae the anterior origin differs distinctly

from the condition described for Aramus and the cranes by

arising from the postorbital process. In Rallus the poste-

rior origin comes mainly from the anterior edge of M. pec-

toralis and the anteroventral corner of the sternum, but in






7

Fulica it arises mainly from the sternum and sternoclavicular

ligament (in Aramus it arises mainly from the furculum). In

Rallus (and Aramus) the posterior origin is dorsal to the

origin of M. tracheohyoideus, with the bellies of the two

muscles closely fused, but in Fulica the posterior origin is

ventral to the origin of M. tracheohyoideus, and the bellies

are only weakly fused.

Summary. The muscle in Aramus is long and has two ori-

gins. In the cranes, Balearica agrees, but in Grus it has

become extremely shortened and has lost the posterior origin.

In the rails the muscle is long with both origins present,

but the anterior origin lies further forward on the skull.


2. M. cucullaris, cephalic part

Moderately thin sheet. Covers posterior edge of skull

and dorsolateral portion of anterior fourth of neck. At-

taches to skull, to third, fourth, and fifth cervical verte-

brae, and to underlying muscles.

Right and left muscles essentially fused into single

sheet by continuation of fascia on superficial and deep sur-

faces. These fascial sheets enclose between them the paired

anterior belly of M. biventer cervicis. Muscle lies deep to

M. dermo-temporalis. Lateral portion contacts posterodorsal

edges of third, fourth, and fifth fasciculi of M. rectus

capitis superior, posterodorsal edge of M. depressor

mandibulae, and anterodorsal corner of M. rectus capitis

lateralis. Superficial to M. splenius capitis, M. splenius

accessorius, Mm. intertransversarii between axis and fourth






8

cervical, and to anterior portion of M. spinalis cervicis.

Origin. By tendinous sheet from dorsolateral surface

of a dorsal tubercle on diapophysis of fourth cervical verte-

bra and by fleshy origin from similar location on third cer-

vical. Also originates by fleshy fibers from bony, lateral

bar connecting prezygapophysis with postzygapophysis on

third and fourth cervicals, by small portion arising from

fifth cervical, and by fleshy fibers from Mm. intertrans-

versari and from third, fourth, and fifth fasciculi of

M. rectus capitis superior.

Insertion. Mainly by fibrous sheet, about 3 mm long,

onto thin, transverse line on dorsal and lateral edges of

occipital region of skull, about 1 mm dorsal to insertion of

M. biventer cervicis on occipital crest. Insertion extends

laterad from middorsal line, then ventrad to meet and fuse

with most dorsal portion of M. depressor mandibulae. Fuses

by loose fibers to dorsal edge of M. rectus capitis

lateralis, to anterior regions of M. cucullaris and M.

splenius capitis, and contacts dorsal edge of anterior region

of origin of M. dermo-temporalis.

Action. One muscle extends head dorsolaterally, and

both act together to extend head dorsally.

Comparisons. In the Gruidae the attachments in Balearica

are quite similar to those of Aramus and are partly so in

Grus, although Fisher and Goodman omitted some details be-

cause of obscuring fascial attachments. The fusion to M.

rectus capitis lateralis and M. depressor mandibulae is






9

present in Balearica but absent in Grus because the belly is

narrower.

The Rallidae agree with Aramus except in attachments to

adjacent muscles. In Rallus the contact with M. depressor

mandibulae is smaller than in Aramus because of partial sep-

aration by M. rectus capitis lateralis. In Fulica the mus-

cle contacts neither M. rectus capitis lateralis nor M. de-

pressor mandibulae.

Summary. The muscle attaches to M. depressor mandibulae

and M. rectus capitis lateralis in Aramus, Balearica, and

Rallus, but in the more specialized Grus and Fulica there is

no contact with these muscles because the belly is narrower.


3. M. biventer cervicis

Very narrow and elongate, composed of two bellies con-

nected by flattened tendon. Lies just lateral to middorsal

line along all except posterior end of neck. Attaches to

skull anteriorly, to fascia and to M. spinalis cervicis

posteriorly.

Anterior belly begins just posterior to skull and ex-

tends to about middle of third cervical. Muscle continues

as tendon from middle of third cervical to middle of ninth

cervical, where posterior belly begins. This belly extends

to about posterior end of thirteenth cervical, where muscle

again becomes tendinous. Fibrous connections join right and

left muscles across mid-line at level of posterior end of

thirteenth and at posterior end of fourteenth cervicals.






10

Right and left members lie alongside each other, sepa-

rated by middorsal line, and anterior bellies fuse in crani-

al half. Anterior belly enclosed within fascial sheets of

M. cucullaris, cephalic part. Most of muscle posterior to

M. cucullaris lies in trough along dorsomedial edge of M.

spinalis cervicis. Connects to latter muscle only at poste-

rior end, but is tightly held against it by strong sheet of

connective tissue enclosing both. Anterior end of muscle

lies superficial to M. splenius capitis and to portions of

Mm. splenii colli.

Origin. By thin tendon, entirely from dorsal surface

of median portion of tendinous area of M. spinalis cervicis

near posterior end of fourteenth cervical.

Insertion. By short but wide aponeurosis from cranial

end of anterior belly, onto thin edge of occipital crest of

skull, just deep to insertion of cephalic part of M. cucul-

laris and in contact with dorsal edge of insertion of M.

splenius capitis. Tendon strong in most medial one-sixth,

weaker laterally. Medial edge meets that of opposite muscle

at middorsal line.

Action. Extends head and straightens neck.

Comparisons. In the Gruidae the posterior belly is lo-

cated between the twelfth and fifteenth cervicals (between

ninth and thirteenth in Aramus). In Balearica the right and

left anterior bellies are fused in less than the anterior

fourth (in the anterior half in Aramus) and apparently are

not fused at all in Grus. In Balearica (and Aramus) the





11

anterior belly is enclosed between the fascial layers of the

cephalic part of M. cucullaris, but in Grus the anterior

belly is completely deep to that muscle. In both cranes the

tendon of origin is fused to the tendon of M. spinalis

cervicis but can be traced to an attachment on the eighteenth

cervical in Balearica and on the sixteenth in Grus (in Aramus

the origin can be traced only to the tendon). In both cranes

the insertion is partly fleshy and quite narrow, representing

only the stronger, medial portion of the inserting tendon of

Aramus.

In the Rallidae the posterior belly in Rallus is located

between the fifth and tenth cervicals, and in Fulica between

the seventh and eleventh. In both rallids the right and left

anterior bellies are fused only at the extreme anterior end.

In both rails (and in Aramus) the anterior belly is enclosed

within the cephalic part of M. cucullaris. In both rallids

the muscle arises fleshily from M. spinalis cervicis (ten-

dinously in Aramus). In both rails the insertion is much

narrower and more medial than in Aramus.

Summary. The location of the posterior belly in the

limpkin is intermediate between that of the cranes and rails,

probably because of size differences. The extent of fusion

between right and left anterior bellies is greatest in Aramus,

intermediate in Balearica, least in the rallids, and appar-

ently lacking in Grus. The wide, lateral extension of the

insertion is unique in the limpkin.








4. M. splenius capitis

Wide and thick anterior end tapers to small posterior

end, giving triangular appearance in dorsal view. Occupies

most of dorsal half of extreme anterior end of neck. At-

taches to skull, to axis, and to surrounding muscles.

Two muscles of pair partially connected across mid-line.

Most of muscle lies deep to cephalic part of M. cucullaris,

and small ventrolateral portion covered by M. depressor

mandibulae and M. rectus capitis lateralis. Lies dorsal to

region of fusion of second to fifth fasciculi of M. rectus

capitis superior. Superficial to all of first and anterior

end of second Mm. interspinales, and to anterior one-third

of M. splenius accessorius.

Origin. Fleshy and tendinous, primarily from axis and

atlas and from fascia connecting atlas to skull, with some

tendinous origin from dorsal raphe of connective tissue,

slightly posterior to axis. Much of origin arises from

neural spine of axis, by small and tendinous anteromedial

components and by mixed fleshy and tendinous components from

anterolateral face of neural spine. Remainder of origin

fleshy, from dorsal surface of atlas and fascia anterior to

atlas, and almost contacts insertion.

Insertion. On all but ventromedial portion of occipital

region of skull, including part of membrane closing occipital

fontanelle, extending onto depression on opisthotic process.

Deeper portions of insertion fleshy, with more superficial

components tendinous. Bordered dorsally by insertion of







M. biventer cervicis; some fibrous connection to overlying

anterior end of cephalic part of M. cucullaris. Partly fused

laterally to underside of insertion of M. rectus capitis

lateralis, which in turn is fused to underside of origin of

M. depressor mandibulae. Bordered ventrolaterally by ventro-

medial portion of origin of M. depressor mandibulae, and has

some fleshy insertion on posterodorsal region of belly of

same portion.

Action. One muscle turns head, but two act together to

extend head dorsally.

Comparisons. In the Gruidae the thickness and insertion

of the muscle in Balearica are as in Aramus, but in Grus the

belly is thinner, and the area of insertion correspondingly

narrower. In Balearica, but not in Grus (or Aramus), a par-

tial separation is present in the posterior end. In Balearica

only, the muscle fuses to M. splenius accessorius. Only Grus

lacks the fusion of the muscle to M. rectus capitis lateralis.

In both cranes the muscle differs from that of Aramus in

arising from fascia over the atlas instead of directly from

the atlas and from fascia directly anterior to it. Both

cranes differ from Aramus in lacking the portion of the ori-

gin posterior to the axis. In Balearica the origin fiom the

spine of the axis is narrowly restricted to the mid-line, but

in Grus (and Aramus) it is wider.

In the Rallidae the belly is thinner than in Aramus,

especially in Fulica. Both rails agree with the limpkin in

the connections of the muscle to adjacent ones. In both








rallids the origin from the axis is much narrower than in

Aramus, being restricted to the area of the mid-line. The

remainder of the origin agrees in Rallus and Aramus, but in

Fulica it arises from fascia over the axis, and the portion

posterior to the axis is absent.

Summary. Of the seven variations in this muscle listed

above, the two cranes agree in only two points and are simi-

lar to each of the other three forms in at least as many.

The two rails agree in only four, and the greatest number of

similar points (six) occurs between Aramus and Rallus.

Aramus has the least agreement with Balearica. The sporadic

distribution of characters seems to indicate adaptability in

this muscle.


5. M. splenius accessorius

Small, elongate, and flattened. Runs diagonally on

dorsolateral aspect of anterior region of neck. Attaches to

first three cervical vertebrae.

Although Fisher and Goodman considered this muscle as

being probably related to M. splenius capitis, it may be

more closely related to M. spinalis cervicis-Mm. splenius

colli complex.

Anterior half deep to M. splenius capitis, and poste-

rior half deep to M. biventer cervicis and M. cucullaris,

cephalic part. Contacts dorsal edge of first of Mm. inter-

transversarii. Anterior portion superficial to lateral edge

of first M. interspinalis and to posteromedial portion of

second fasciculus of M. rectus capitis superior. Posterior






15

portion superficial to posterolateral part of second M. inter-

spinalis and to tendinous insertion and part of belly of an-

terior end of M. spinalis cervicis-Mm. splenius colli complex.

Origin. Mixed fleshy and tendinous from anterolateral

side of neural spine of third cervical, and from dorsolateral

extent of postzygapophysis of axis. Origin loosely attached

along posterolateral edge to adjacent anterior belly of an-

teriormost part of Mm. splenius colli.

Insertion. Anterior third of muscle comprised of thin,

strap-like tendon which attaches to posterior process of

postzygapophysis of atlas. Underside of belly has fleshy at-

tachment to dorsolateral extent of postzygapophysis of axis,

and this area of attachment considered to have functional

components of both origin and insertion.

Action. Turns upper end of neck laterad.

Comparisons. In the Gruidae, Balearica has the muscle

thoroughly attached to M. splenius capitis and M. spinalis

cervicis, but in Grus (and Aramus) these attachments are

slight or lacking. In Balearica the muscle arises and in-

serts on the axis in a manner more complex than in Aramus,

but in Grus these attachments are absent. In Balearica the

main insertion is not on the postzygapophysis of the atlas

(as it is in Aramus) but is on the dorsal half of the neural

arch. In Grus this is the only insertion, which Fisher and

Goodman (1955) describe as being on the most ventral and lat-

eral extent of the atlas. This origin differs remarkably

from all other forms studied, unless the arch of the atlas


was meant.





16

In the Rallidae the belly of the muscle in Rallus lies

between the third cervical and the axis, and passes medial to

the postzygapophysis of the axis. In Fulica the belly lies

between the axis and atlas and passes lateral to the post-

zygapophysis of the axis. In both rallids the insertion onto

the axis is larger than in Aramus, and this is the main in-

sertion in Rallus. In both rallids the atlantal insertion

is on a facet on the postzygapophysis instead of on a defi-

nite process as in Aramus.

Summary. This muscle is somewhat variable in detail,

especially within the cranes and to a lesser extent between

the gruids and Aramus. The two rails show good agreement

with each other and with the limpkin. Balearica resembles

Aramus slightly more than does Grus, and Fulica is more like

the limpkin than is Rallus.


6. M. depressor mandibulae

Short, somewhat thick, and partially separated into lat-

eral and medial parts. Located at angle of jaw. Attaches to

skull and to posterior end of mandible.

Deep, in part, to anterior end of M. dermo-temporalis

and to dorsal edge of M. geniohyoideus. M. splenius capitis

has part of insertion on posterolateral extent of median

part, and portion of posterodorsal edge fused with M. cucul-

laris. Anteroventral edge contacts posterior end of M.

stylohyoideus and contacts posterior edge of superficial

part of M. pteryqoideus ventralis on both lateral and medial

sides of mandible. Anterodorsal edge of belly fused to wall






17

of external auditory meatus. Superficial to anterior ends

of M. rectus capitis lateralis, M. rectus capitis superior

complex, and to Liqamentum mandibulae.

Origin. Arises from skull, mainly from region of

opisthotic process. Origin and belly incompletely divided

into lateral and medial parts by inserting aponeurosis of M.

rectus capitis lateralis. Lateral portion composed of fleshy

fibers arising from ventrolateral region of occipital crest,

along posterior edge of anterior origin of M. dermo-temporalis,

and these fibers fuse with aponeurosis of M. rectus capitis

lateralis. Medial portion has mixed origin from posteroven-

tral surface of opisthotic process. Anterior to separation

by M. rectus capitis lateralis, two portions join with fleshy

origin from all but lateral surface of opisthotic process,

with strong tendon from anterior edge of opisthotic process,

and with tendinous fibers from ventrolateral edge of basi-

temporal plate. Lateral and medial portions of muscle remain

partially separable through middle of belly.

Insertion. Fleshy, except for tough, superficial

fascial sheet. Attaches to most of posterior face of mandible.

Action. Opens mouth by depressing mandible.

Comparisons. In the Gruidae the muscle differs from

that of Aramus in contributing to the origin of M. dermo-

temporalis and in having much less connection to M. rectus

capitis lateralis. In Balearica the origin extends to the

dorsal edge of the occipital region of the skull, and the

belly is slightly fused to the insertion of M. splenius






18

capitis. In Grus (and Aramus) the origin does not extend so

far dorsad, and it does not connect to the insertion of M.

splenius capitis. Balearica resembles Aramus but differs

from Grus in having part of the origin from the basitemporal

plate.

In the Rallidae the muscle in Rallus is divided into

anterodorsal and posteroventral portions, unlike the divi-

sion into lateral and medial portions in Fulica (and Aramus).

In both rallids the muscle resembles that of Aramus in not

contributing to the origin of M. dermo-temporalis or fusing

to the insertion of M. splenius capitis. Both rallids differ

from Aramus in having part of the origin from the basitemporal

plate and in having no fusion of the muscle to the cephalic

part of M. cucullaris.

Summary. Only minor variations are present, and points

of comparison indicate that Aramus has similarities to both

cranes and rails.


7. M. rectus capitis lateralis

Thick, fleshy, horizontally oriented sheet at posterior

end tapers to much narrower, vertically oriented aponeurosis

at anterior end; runs from posteroventral to anterodorsal

locations. Lies on side of anterior end of neck. Attaches

to second, third, and fourth cervicals and to skull.

Anterodorsal end lies partly deep to anterior portion

of M. dermo-temporalis, to ventrolateral corner of insertion

of cephalic part of M. cucullaris, and to a posterodorsal

portion of lateral part of M. depressor mandibulae.








Posteroventral end partly covered by anterior end of M. flexor

colli brevis. A short length of dorsal edge is fused to ven-

tral edge of cephalic part of M. cucullaris near anterior

ends of the two muscles. Ventral side of belly very loosely

connected to dorsal side of M. rectus capitis ventralis.

Posterior portion contacts M. flexor colli profundus. At

anterior end muscle lies superficial to ventrolateral edge

of origin of M. splenius capitis and to posterodorsal extent

of medial origin of M. depressor mandibulae. Middle of bel-

ly superficial to portions of last three fasciculi of M.

rectus capitis superior.

Origin. Arises by fleshy and tendinous fibers from

ventrolateral edges of hypopophyses of second, third, and

fourth cervicals. At extreme posterior end has some fleshy

fusion to M. rectus capitis ventralis, and origins of two

are contiguous.

Insertion. By thin aponeurosis, mostly in common with

lateral part of M. depressor mandibulae, onto narrow line on

ventrolateral portion of occipital crest and extending onto

posterolateral edge of opisthotic process. Most of attach-

ment lies adjacent to posterior edge of anterior origin of

M. dermo-temporalis. Insertion separates origin of M. de-

pressor mandibulae into lateral and medial parts. Dorsal

tip of insertion lies deep to ventrolateral edge of cephalic

part of M. cucullaris, near its insertion, and anterior half

of dorsal border loosely joined by connective tissue to lat-

ter muscle, although bellies not in contact.






20

Action. One muscle acts to turn head laterad, and both

together extend (beugung of Gadow, 1893) head on neck.

Comparisons. In the Gruidae the attachment in Balearica

to M. rectus capitis lateralis is as in Aramus, except for

being weaker. In Grus a strong attachment exists between

these two muscles, but only on the left side. The asymmetry

is apparently correlated with the position of the trachea.

Both cranes differ from Aramus in having none of the muscle

deep to or fused with the cephalic part of M. cucullaris and

none superficial to M. depressor mandibulae. In Balearica

the origin from the second through the fifth cervicals, but

in Grus only from the third and fourth cervicals (in Aramus

it arises from the second through the fourth). In Balearica

the insertion is as in Aramus, attaching to a long line by a

thin, wide aponeurosis, but in Grus a thickly rounded tendon

inserts on a small oval facet. Both gruids differ from

Aramus in lacking a common insertion with M. depressor

mandibulae.

In the Rallidae the connection to M. rectus capitis

ventralis is symmetrical, but it is stronger in Fulica. In

both rallids then fusion to M. cucullaris and the connection

to M. depressor mandibulae are stronger than in Aramus.

Summary. Variations among the three families are slight.

Minor characteristics of Aramus agree well in Balearica, but

poorly in Grus. The Rallidae are rather constant and agree

well with Aramus.





21

8. M. rectus capitis superior

Relatively thick and composed of five fasciculi, appear-

ing in lateral view as an elongate triangle with apex at pos-

terior end. Located on side of upper neck. Attaches to

first five cervicals, to skull, and to parts of M. flexor

colli brevis and M. flexor colli profundus.

First four fasciculi diverge from small, common ante-

rior end, but fifth largely independent. Each successive

fasciculus attaches to cervical vertebra of corresponding

numbers, although third and fifth have additional attach-

ments. Successive fasciculi, therefore, of increasing thick-

ness and length from anterior to posterior ends. Separations

between last three fasciculi indistinct in one specimen.

Fourth fasciculus partly superficial to fifth, and some

fleshy connection exists between them. Much of muscle com-

plex lies deep to M. rectus capitis lateralis. Most of dor-

sal edge of complex adjoins first five Mm. intertransversarii

and ventrolateral edge of cephalic part of M. cucullaris.

More posterior portions dorsal to posterior portions of M.

rectus capitis lateralis and M. flexor colli brevis. Super-

ficial to all but posterior end of M. flexor colli brevis,

to anterior end of M. longus colli, and to anterior end of

M. flexor colli profundus.

Origin. First fasciculus arises fleshily from side of

atlas, between dorsolateral border of condylar facet and in-

sertion of M. splenius accessorius on posterior process of

postzygapophysis. Second fasciculus originates fleshily and





22

tendinously from side of axis, along bony ridge extending

from prezygapophysis to postzygapophysis. Third fasciculus

has fleshy and tendinous origin, similar to that of second,

from lateral bar of third cervical, but has additional

fleshy origins from fused rib of third cervical and from

centrum of second cerfical. Fourth fasciculus also has

mixed origin from whole length of lateral bar of fourth cer-

vical and from fused rib of same vertebra. Fifth fasciculus

arises fleshily from side of axis and from large areas on

fused ribs of third and fourth cervicals, alongside origins

of previous two fasciculi. Fifth fasciculus arises also

from lateral bars of third and fourth cervicals and from side

of prezygapophysis of fifth cervical. Small, deep slip arises

in common with main part of fifth fasciculus and with M.

flexor colli brevis. All fasciculi but first have some of

origin in contact with adjacent portions of Mm. intertrans-

versarii, and all but first and second fasciculi have origins

connected to ventrolateral portions of origin of cephalic

part of M. cucullaris. Fifth fasciculus loosely connected

at posterior end to M. flexor colli brevis.

Insertion. Fasciculi one through four have common in-

sertion, by small tendon, onto triangular area on postero-

lateral region of basitemporal plate; this surface of at-

tachment faces posteroventrally. Fifth fasciculus has inde-

pendent tendinous insertion on posteriorly directed process

from ventrolateral part of atlas, small attachment to hy-

papophysis of axis, and small deep slip that passes sepa-

rately to attach to first fasciculus of M. flexor colli








profundus, which inserts on pleurapophysis of axis.

Action. One muscle turns head and upper neck ventro-

laterad, but both muscles together bend head and upper neck

ventrad.

Comparisons. In the Gruidae Balearica is unique in

having the third fasciculus divided into two parts. In

Balearica the origins for fasciculi three, four, and five

are on a ligament alongside the centra of the vertebrae in-

volved (this ligament is ossified in Aramus), but in Grus

the ligament is apparently absent, and the fasciculi arise

from the centrum. Balearica agrees with Aramus in having

several origins for each of these three fasciculi, but Grus

has few. In Balearica the deep slip of the fifth fasciculus

is divided into outer and,inner parts, but only one exists

in Grus (and Aramus). The inner part in Balearica inserts

independently and seems to correspond to the single slip of

the others; the outer part inserts with the main fifth

fasciculus, from which it is apparently derived. In Balearica

and Grus the main insertion is partly on fascia connecting to

the skull (directly to the skull in Aramus). The muscle in

Grus is unique in having a common insertion with M. flexor

colli brevis.

In the Rallidae the origins of fasciculi three, four,

and five have fewer attachments, especially to pleurapophyses,

than in Aramus. In Rallus the fifth fasciculus is short and

is completely deep to the third and fourth, but at least

part of the fifth is exposed in Fulica largelyy exposed in





24

Aramus). In Rallus the fifth fasciculus has no origin from

the fifth cervical, but some of the origin arises from that

vertebra in Fulica (and Aramus). The fifth fasciculus in the

rallids lacks the deep slip found in Aramus. In Rallus the

fifth fasciculus inserts independently as in Aramus, but a

common insertion with M. flexor colli brevis exists in

Fulica. Individual variation was found in one specimen of

Rallus, in which the third and fourth fasciculi were in-

separably fused on one side.

Summary. The inconstancy of the muscle indicates

adaptability. The Rallidae are unique in lacking the deep

slip of the fifth fasciculus. Evidences of additional

separation (in Balearica) and fusion (in Rallus) of fasciculi

indicate that these slips probably evolved from a single,

larger muscle, and rearrangement is still occurring.


9. M. rectus capitis ventralis

Elongately triangular, with slightly wider anterior end

tapering uniformly to pointed posterior end; composed of

lateral and medial parts. Located on ventral side of neck

in region of throat. Attaches to first five cervicals, to

connective tissue in mid-line, loosely to surrounding mus-

cles, and to skull.

Lateral part has irregular, transverse partition of

connective tissue in middle of belly, causing muscle to ap-

pear to be formed by fusion of ends of two shorter muscles.

Medial part composed of loosely connected bundles.






25

Lateral part longer and partly superficial to medial

part. Right and left lateral parts loosely connected poste-

rior to medial part. Right and left medial parts in contact

throughout length at mid-ventral line, strongly fused at an-

terior ends. Lateral and medial parts mostly very loosely

connected, but somewhat fused near insertions. Muscle lies

just dorsal to esophagus, with portion of posterior end deep

to M. longus colli. Lateral side of muscle contacts medial

side of M. rectus capitis lateralis and M. longus colli, and

posterior end of each part contacts M. rectus capitis supe-

rior. Medial part contacts an anterior portion of insertion

of M. flexor colli profundus.

Origin. Lateral part arises fleshily from ventral face

of hypapophysis of fourth cervical, ventral surface of

centrum of fifth cervical, and from connective tissue around

carotid artery ventral to sixth cervical. Medial part takes

fleshy and tendinous origin from narrow area along mid-

ventral line, including hypapophyses and fascia between

hypapophyses, of first four cervical vertebrae. Lateral

part has some connection to M. lonqus colli at posterior end.

Origin of medial part loosely connected to medial side of

origin of M. rectus capitis lateralis, to an anterior portion

of insertion of M. flexor colli profundus, and appears to be

continuous with its own insertion on skull.

Insertion. Lateral part inserts by narrow, rounded

tendon onto small tubercle (probably same as occipital pro-

cess of Fisher and Goodman, 1955) on posterolateral area of






26

basitemporal plate. Medial part inserts fleshily on larger

area, including nearly all of ventral surface of basitem-

poral plate. Lateral and medial parts somewhat fused near

origin.

Action. Flexes head on neck.

Comparisons. In the Gruidae the muscle is symmetrical

in Balearica (and Aramus) but isasymmetrical in Grus. The

transverse partition in Aramus is lacking in both gruids.

Balearica resembles Aramus in having the two lateral parts

only weakly connected. In Grus the right and left medial

parts are inseparably fused, and the two lateral parts are

much more closely connected than in Balearica (or Aramus).

In Balearica the attachment to M. rectus capitis lateralis

is symmetrical and slightly stronger than in Aramus, but in

Grus it is much stronger on the left side and absent on the

right. In Balearica (and Aramus) the lateral part originates

bilaterally from the fourth and fifth cervicals and connec-

tive tissue below the sixth. In Grus the right lateral part

arises from the fourth and sometimes the fifth cervicals, but

the left one arises from the fourth, fifth, and sometimes the

sixth cervicals. In Balearica (and Aramus) the origin of

the medial part is from the skull to the fourth cervical.

In Grus the left medial part agrees, but the right only ex-

tends posteriad to the third cervical. In Balearica (and

Aramus) the insertion of the lateral part is located further

posterior than in Grus. This attachment is elongate in

Balearica and oval in Grus (rounded in Aramus).





27

In the Rallidae the muscle is symmetrical in Rallus,

but the right lateral part is sometimes longer in Fulica

(this asymmetry is opposite to that of Grus). Neither rallied

has the transverse partition of Aramus. In Rallus the poste-

rior extent of the lateral part reaches the connective tis-

sue ventral to the sixth cervical, but only reaches to the

region of the fifth cervical in Fulica.

Summary. Minor features are inconsistent within the

cranes, consistent within the rallids, with better agreement

with Aramus. The limpkin agrees best with Balearica in the

cranes and with Rallus in the rails. The inconsistency

within the gruids is apparently a consequence of the special-

izations in Grus, involving asymmetry and coiling of the

trachea. Slight asymmetry sometimes occurs in Fulica, but

it is opposite to that of Grus.


10. M. flexor colli brevis

Elongately triangular, with apex at posterior end; ob-

liquely divided into four separate fasciculi. Located on

lateral portion of upper neck. Attaches onto second through

seventh cervicals, to M. longus colli, to Mm. intertransversarii.

and loosely to M. rectus capitis superior.

Anterior half located deep to M. rectus capitis superior,

and edges of posterior portion partly deep to Mm. intertrans-

versarii. Partly in common with anterior end of M. lonqus

colli. Ventral portions contact origins of M. rectus capitis

lateralis. Superficial to most of M. flexor colli profundus

and portions of Mm. intertransversarii.





28

Origin. First and most anterior fasciculus originates

fleshily from lateral surface of centrum of third cervical

and fleshily from lateral bar of fourth cervical. Second

fasciculus takes fleshy origin from prezygapophysis and lat-

eral surface of centrum of fifth cervical. Third fasciculus

arises from postzygapophysis of fifth cervical. Fourth

fasciculus has origin from pleurapophysis of sixth and an-

terolateral corner of prezygapophysis of seventh cervical.

Three posterior parts loosely connected to Mm. intertrans-

versarii.

Insertion. First fasciculus inserts partly along poste-

rior edge of pleurapophysis of third cervical and remainder

fuses with fifth fasciculus of M. rectus capitis superior.

Second fasciculus inserts on pleurapophysis of third cervi-

cal in common with portions of M. longus colli. Third fas-

ciculus inserts on distal tip of pleurapophysis of fourth

cervical. Fourth fasciculus inserts on pleurapophysis of

fifth cervical and sometimes on distal end of pleurapophysis

of fourth cervical.

Action. One muscle bends upper neck ventrolaterad, but

both together turn upper neck ventrad.

Comparisons. In the Gruidae Balearica has the muscle

divided into fasciculi as in Aramus. Divisions are apparently

similar in Grus, but Fisher and Goodman (1955) did not list

them in detail. In Grus a portion of the most anterior fas-

ciculus arises from the axis and the third cervical and in-

serts on the fifth fasciculus of M. rectus capitis superior,





29

but this fasciculus is an inseparable part of M. rectus

capitis superior in Balearica (and Aramus). The anterior

portion of the muscle has apparently changed its associa-

tions. This supports the idea of Fisher and Goodman (1955)

that M. flexor colli brevis could be considered as slips of

the M. rectus capitis superior complex. The second and third

fasciculi in Balearica (and Aramus) apparently represent di-

visions of a single fasciculus arising from the fifth cervi-

cal in Grus. Both cranes disagree with Aramus in having a

portion originating from the pleurapophysis of the fifth

cervical. In Balearica (and Aramus) the origin has compo-

nents, not present in Grus, from the fourth and seventh

cervicals.

In the Rallidae the muscle is divided as it is in Aramus.

Both rallids differ from Aramus in possessing, as part of M.

flexor colli brevis, the portion that arises from the atlas

and third cervical and attaches to the fifth fasciculus of

M. rectus capitis superior. In Rallus only, a small portion

arises from the fifth cervical. In Fulica (and Aramus) por-

tions arise from the fourth and seventh cervicals, but in

Rallus the origin from the seventh is lacking.

Summary. The major features of this muscle are funda-

mentally similar but show considerable variation in the ar-

rangement of the parts among the three families, as well as

within the Gruidae and the Rallidae. In some small details

of attachment there is greater similarity between Aramus and

Balearica than between Balearica and Grus. Intrafamilial





30

variation, along with distinct interfamilial similarity, in-

dicates that this muscle has been variously specialized in

different genera.


11. M. flexor colli profundus

A disjunct series of six fasciculi connecting anterior

vertebrae. Located on ventrolateral side of upper neck. At-

taches to first six cervicals, to M. lonqus colli, and to

M. rectus capitis superior.

Most of muscle lies deep to M. flexor colli brevis, and

small middle portion deep to M. rectus capitis superior.

Posterior end deep to M. longus colli, and third fasciculus

deep to one of Mm. intertransversarii. Ventral extent in

contact with medial part of M. rectus capitis ventralis and

posterior portion of M. rectus capitis lateralis.

Origin. First two fasciculi closely connected. First

fasciculus arises from anteroventral edge of pleurapophysis

of third cervical. Second fasciculus arises from medial side

of pleurapophysis and anteroventral corner of centrum of

third cervical. Third fasciculus has fleshy and tendinous

origin from anteromedial edge of pleurapophysis of fourth

cervical, from lateral part of centrum and hypapophysis of

third cervical, and loosely from medial side of pleurapophy-

sis of third cervical. Fourth fasciculus arises fleshily or

by strong, narrow tendon from anterior face of prezygapophy-

sis of fifth cervical and fleshily from lateral side of cen-

trum and medial side of pleurapophysis of fourth cervical.

Fifth fasciculus has mostly fleshy origin from anterior





31

corner of ventrolateral portion of sixth cervical and fleshy

origin from ventrolateral edge of full length of centrum of

fifth cervical. Sixth fasciculus arises, mostly tendinously,

from sixth cervical, just ventral to and in contact with

origin of fifth fasciculus pnd partly in common with origin

of one of fasciculi of M. longus colli.

Insertion. First fasciculus receives medial slip of

fifth fasciculus of M. rectus capitis superior and inserts

tendinously on pleurapophysis of axis. Second fasciculus

inserts fleshily on most of lateral face of hypapophysis of

axis and on ventral extent of atlas. Third fasciculus has

mixed insertion along ventrolateral edge of hypapophysis of

axis. Fourth fasciculus has fleshy insertion onto postero-

lateral portion of hypapophysis of third cervical. Fifth

fasciculus inserts on posterior corner of ventrolateral re-

gion of centrum of fourth cervical. Sixth fasciculus has

fleshy insertion onto ventrolateral edge of full length of

centrum of fifth cervical but may also insert with fifth

fasciculus on fourth cervical. Insertions of third and

fourth fasciculi contact origin of M. rectus capitis lat-

eralis. Insertion of fifth fasciculus contacts origin of

medial part of M. rectus capitis ventralis and part of in-

sertion of M. lonqus colli.

Action. Contraction of muscle on one side bends upper

neck in ventrolateral direction, but both sides together bend

upper neck in ventral direction.

Comparisons. In the Gruidae, Balearica agrees with

Aramus in having the first two fasciculi fused, but in Grus





32

they are separate. In Balearica the fifth and sixth fas-

ciculus each have a connection to a portion of M. loncus

colli, but in Grus only the fifth is so connected (neither

connection exists in Aramus). The third fasciculus in

Balearica originates from the centrum, but not from the hy-

papophysis or pleurapophysis of the third cervical; all

three origins are present in Grus (and Aramus). In Balearica

(and Aramus) the fourth fasciculus arises partly from the

pleurapophysis of the fourth cervical, but this origin is

not found in Grus. In Balearica the third fasciculus has an

additional deep portion that inserts on the whole lateral

face of the hypapophysis of the third cervical, but in Grus

(as in Aramus) this portion is not present, and the insertion

of the third fasciculus is only on the axis.

In the Rallidae the first two fasciculi differ fmrm the

ones in Aramus in being separate. In Rallus the third fas-

ciculus has a connection to M. longus colli, not present in

Fulica (or Aramus). The fifth and sixth fasciculi are sep-

arate in Rallus (and Aramus), but they are strongly connected

in Fulica. In Rallus (as in Aramus) the insertions of the

first and second fasciculi occupy nearly all of the lateral

face of the hypapophysis of the axis, but these insertions

occupy only very small areas in Fulica. In Rallus the fifth

fasciculus is large and inserts partly on the third cervical,

whereas this part is smaller and has no insertion on the

third cervical in Fulica (or Aramus).

Summary. The variations in this muscle among the genera

are slight, but inconsistent within the Gruidae and Rallidae.






33

The divergences primarily involve small variations in fas-

cicular attachments of the various parts.


12. M. adductor mandibulae
externus superficialis

Wide and flat in posterior third; narrow and somewhat

thickened in anterior two-thirds. Runs longitudinally along

lateral portion of skull. Attaches to temporal fossa, to

mandible, to M. depressor mandibulae, and to deeper adductor

muscles.

Bridged over by postorbital ligament and jugal bar of

skull. Ventral edge of posterior half closely attached to

dorsal edge of rostral slip of M. adductor mandibulae ex-

ternus profundus, fused to anterior side of posterodorsal

extent of M. depressor mandibulae and contacts anterior ori-

gin of M. dermo-temporalis. Superficial to M. adductor

mandibulae externus medialis and M. adductor mandibulae

medius.

Origin. Arises fleshily from posterior two-thirds of

temporal fossa, and also by ossified tendon continuous with

bone of ventral portion of temporal fossa. Ventral edge of

origin arises from tendon of origin of M. adductor mandibulae

medius.

Insertion. Two separate insertions. One mainly fleshy,

on superficial fascia and ossified tendon of most lateral

part of M. adductor mandibulae medius, with superficial fas-

cia extending farther to insert directly on bone of mandible

along anterodorsal edge of latter muscle. Other part of





34

insertion attaches onto coronoid process of mandible, by

very strong tendon partly in common with insertion of M. ad-

ductor mandibulae externus medialis.

Action. Closes mouth by adducting mandible.

Comparisons. In the Gruidae the muscle in Balearica is

undivided as in Aramus, but in Grus it is composed of sepa-

rate superficial and deep parts. In Balearica the muscle is

separated from M. depressor mandibulae, but it has intimate

contact with the anterior origin of M. dermo-temporalis.

Grus agrees with Aramus in having the muscle contact M. de-

pressor mandibulae, but in neither is there close contact

with M. dermo-temporalis. In Balearica a narrow, ossified

tendon originates from the ventral portion of the temporal

fossa in common with M. adductor mandibulae medius (the ten-

don is similar but separate in Aramus). This tendon corres-

ponds to the independent, unossified, main origin of the su-

perficial part in Grus, and the remainder of the origin of

the superficial part in Grus is from fascia of the deep part.

The other origin in Balearica (and Aramus) arises fleshily

from most of the temporal fossa and corresponds to the fleshy

origin of the deep part from the dorsoposterior region of the

temporal fossa in Grus. In both cranes the most anterior in-

sertion is by a strong tendon (unlike the weak and super-

ficial fascia attachment in Aramus) on the dorsolateral edge

of the mandible. This is the insertion of only the super-

ficial part in Grus. In Balearica, but not in Grus, there

is a small area (large in Aramus) of fleshy attachment to





35

M. adductor mandibulae medius, just posterior to the previous

tendon. The deeper and more posterior insertion on the coro-

noid process of the mandible is similar in both cranes and

agrees with Aramus, but this is the insertion of only the

deep part in Grus.

In the Rallidae the muscle is divided in the posterior

region into two heads that seem generally equivalent to the

superficial and deep parts in Grus. Fulica is unique in

having some of the deep head superficial to the superficial

head, and in showing individual variation in the size of the

muscle, so that it is sometimes superficial to part of M.

adductor mandibulae externus profundus. In both rallids the

muscle has more extensive contact with M. depressor mandibulae

than in the limpkin, and the posterior portion is overlapped

by M. dermo-temporalis (not overlapped in Aramus) In Rallus

alone, this origin is enclosed by superficial fascia, by

which it is attached to the deep head. The deeper origin in

both rallids is about the same as that of Aramus. In both

Rallus and Fulica (but not in Aramus) each of the two heads

arises partly from M. adductor mandibulae externus medialis.

In both rallids the two heads fuse before inserting. The

most anterior attachment is similar to the corresponding at-

tachment in Aramus, except that it is located more poste-

riorly and lacks attachment to M. adductor mandibulae medius.

Summary. The muscle apparently has undergone several

small-scale modifications in the various genera. It is com-

posed of only one part in Aramus and Balearica, but it is








composed of two parts in Grus and is partly divided in the

rallids. The most distinctive feature is the small, tendinous

origin of the superficial part in Aramidae and Gruidae, con-

trasted with the wide and fleshy attachment of the corres-

ponding origin in Rallidae. In other more minor features

Aramus has more similarity with gruids than with rallids.


13. M. adductor mandibulae
externus profundus

Small, elongate muscle composed of rostral and caudal

parts; rostral part superficial with bipinnate belly. Poste-

rior end of muscle lies just posterior to ear opening. An-

terior end passes beneath postorbital ligament and beneath

posterior end of jugal bar. Attaches to temporal fossa,

quadrate, mandible, and to tendon of origin of lateral part

of M. adductor mandibulae medius.

Anterior end partly deep to lateral part of M. adductor

mandibulae medius. Posterior end in contact with ventral

edge of M. adductor mandibulae externus superficialis and

with anterior origin of M. dermo-temporalis. Middle of belly

attaches to ventral side of tendon of origin of lateral part

of M. adductor mandibulae medius. Superficial to most of

medial part and some of origin of lateral part of M. adduc-

tor mandibulae medius.

Origin. Rostral part arises, partly fleshily and partly

by ossified tendon, from ventral region of temporal fossa,

fleshily from lateral surface of quadrate, and by ossified

tendon from otic process of quadrate. Dorsal edge of origin





37

arises from tendon of origin of M. adductor mandibulae medius.

Caudal part arises fleshily from lateral surface of main body

of quadrate and from proximal part of orbital process of

quadrate, in common with portion of origin of rostral part.

Insertion. Rostral part has mixed insertion, partly by

ossified tendon and partly by fleshy fibers, onto dorsolat-

eral edge of mandible. This attachment partly deep to, and

partly posterior to, insertion of lateral part of M. adduc-

tor mandibulae medius, to which there is some connection.

Caudal part inserts partly fleshily and partly by ossified

tendon, attaching strongly onto dorsal edge of mandible at

level of small foramen in angular bone.

Action. Closes mouth by adducting mandible.

Comparisons. In the Gruidae the muscle in Balearica is

divided, but the superficial part is small and seems to cor-

respond to the upper, tendinous portion of the rostral part

in Grus (and Aramus). The deeper part in Balearica includes

portions corresponding to all the caudal part as well as to

the deeper and more ventral portions of the rostral part of

Grus (and Aramus). This muscle in Balearica is neither con-

nected to nor covered by M. adductor mandibulae medius (con-

nected but not covered in Aramus). In Grus the dorsal end of

the caudal part is fused to the medial slip of the previous

muscle, and the anteroventral portion of the rostral part is

covered by the lateral part of the same muscle. In Grus,

but not Balearica (or Aranus), the dorsal end of the rostral

part is covered by the deep slip of M. adductor mandibulae


externus superficialis.






38

In the Rallidae the muscle is slightly smaller than in

Aramus. In Rallus the rostral and caudal parts are entirely

fused, and in Fulica they are separate only at their inser-

tions (fused only at origins in Aramus). Fulica shows in-

dividual variation in sometimes having the dorsal edge of the

rostral part deep to M. adductor mandibulae externus super-

ficialis, because of variation in the size of the latter

muscle. In Rallus and Fulica (but not in Aramus) the origin

of the rostral part includes portions from the orbital cra-

nium, just medial to the postorbital process.

Summary. Balearica appears somewhat specialized in

having the two parts separated in a different plane from that

of Grus and the non-gruids. In other minor features the

rallids are different from the non-rallids in having the

muscle smaller and in having the two parts mostly fused, al-

though a small amount of similar fusion occurs in Aramus.

The two rallids are also distinct from the other two families

in having the origin extending into the orbit.


14. M. adductor mandibulae
medius

Composed of thin and somewhat spatulate lateral part and

thicker medial part. Located below eye; lateral part one of

most superficial adductors of jaw, medial part deepest adduc-

tor of jaw. Attaches to temporal fossa, to quadrate, to

mandible, and to inserting tendon of M. adductor mandibulae

externus medialis.

Bridged by postorbital ligament and jugal bar. Tendon

of origin of lateral part deep to adjacent edges of





39

M. adductor mandibulae externus superficialis and rostral

part of M. adductor mandibulae externus profundus, where

these two muscles adjoin. Dorsal half of anterior end deep

to and fused with M. adductor mandibulae externus super-

ficialis. Medial part deep to all other adductors of jaw.

Most ventral extent of lateral part contacts superficial part

of M. pterygoideus ventralis. Posterior end of lateral part

superficial to portion of caudal part of M. adductor man-

dibulae externus profundus. Anterior end of lateral part

superficial to anterior end of rostral part of M. adductor

mandibulae externus profundus and to most posterior insertion

of M. adductor mandibulae externus superficialis.

Origin. Lateral part arises by slender, ossified ten-

don from anteroventral extent of temporal fossa. This ten-

don also furnishes part of dorsal edge of origin of rostral

part of M. adductor mandibulae externus profundus and ventral

edge of origin of M. adductor mandibulae externus super-

ficialis. Muscle narrow in proximal third, then belly and

an enclosed ossified tendon flare to become wide and fleshy

in anterior two-thirds. Medial part has mixed origin from

anterior edge of body and anterior and anteromedial edges of

orbital process of quadrate.

Insertion. Lateral part inserts fleshily over region

about 23 mm long, including mandibular foramen. Posterior

edge of insertion on anterior end of rostral part of M.

adductor mandibulae externus profundus, and M. adductor man-

dibulae externus superficialis shares dorsal part of inser-

tion. Medial part inserts narrowly on posterolateral edge


M






40

of mandible just anterior to quadrate and extensively onto

large depression on medial side of mandible. Covers area

from internal articular process to posterior third of mandi-

bular foramen. Tendon of M. pseudotemporalis passes through

medial part, which it partially divides along superficial

side. Tendon of M. adductor mandibulae externus medialis

inserts on anterodorsal edge of medial part.

Action. Closes mouth by adducting mandible.

Comparisons. In the Gruidae the muscle in Balearica

differs fron'that of Aramus in lacking contact with M. ptery-

goideus ventralis, but the contact sometimes exists in Grus.

In Balearica the lateral part is unique in having a large

ossified tendon of origin in addition to the smaller ossi-

fied tendon like that of Grus (and Aramus) and in having a

dense fascial sheet that covers the lateral edge of the

medial part and fuses with the inserting tendon of M. pseudo-

temporalis. Balearica (like Aramus) has no origin of this

muscle from the lateral face of the quadrate, but that area

furnishes a portion of the origin of the medial part in Grus.

In the Rallidae the proximal end of the lateral part is

located farther dorsally and is deep only to M. adductor

mandibulae externus superficialis (in Aramus this portion is

deep to the .latter muscle as well as to M. adductor mandibulae

externus profundus, since it lies beneath the line of junc-

tion between them). The two rallids have only the dorsal

edge of the lateral part deep to the anterior end of M. ad-

ductor mandibulae externus superficialis and have no insertion






41

of that muscle on the lateral part (in Aramus most of the

dorsal half of the lateral part lies deep to M. adductor

mandibulae externus superficialis and furnishes a wide area

of insertion for it). The rallids differ from Aramus in

having the tendinous portion of the origin of the lateral

part unossified.

Summary. In Aramus the muscle agrees somewhat better

with that of Grus than Balearica, but the variations are

mostly minor. The most distinctive characters are the extra

tendon of origin of the lateral part and the dense, lateral

fascia in Balearica, but these apparently are specializa-

tions, since they are not found in Grus or Aramus. The dif-

ferences between the limpkin and the Rallidae are similarly

minor, and the two rallids agree closely, even in small

details.


15. M. adductor mandibulae
externus medialis

Small and elongate muscle. Deepest of adductors in

temporal fossa; located just ventral to orbit. Attaches to

temporal fossa, to M. adductor mandibulae externus super-

ficialis, and indirectly to mandible.

All but anterodorsal edge of muscle deep to anterodorsal

edge of middle of belly of M. adductor mandibulae externus

sunerficialis. Superficial to belly of M. pseudotemporalis

bulbi and to posterodorsal part of origin of M. pesudo-

temporalis.

Origin. Arises partly fleshily and partly by ossified

tendon arising as continuation of bone of temporal fossa.





42

Origin covers small area in anterodorsal region of temporal

fossa, just posterior to posterodorsal part of origin of M.

pseudotemporalis.

Insertion. Belly attaches to ossified tendon of M. ad-

ductor mandibulae externus superficialis and inserts in com-

mon with it on coronoid process of mandible and on anterodor-

sal edge of medial part of M. adductor mandibulae medius.

Muscle therefore inserts indirectly on mandible.

Action. Aids in closing mouth by adducting mandible.

Comparisons. In the Gruidae, Balearica has the origin

larger and more completely aponeurotic than in Grus (or

Aramus). In Balearica the side of the muscle is completely

fused to the inner side of M. adductor mandibulae externus

superficialis, and the insertion is on the same muscle (the

small insertion is the only attachment to that muscle in

Aramus). In Grus there is no attachment to M. adductor

mandibulae externus superficialis, and the insertion is en-

tirely on M. adductor mandibulae medius.

In the Rallidae the belly of the muscle in Rallus lies

between the two parts of M. adductor mandibulae medius, but

does not in Fulica (or Aramus). In Rallus, but not in Fulica

(or Aramus), there is fusion to the dorsal edge of the rostral

part of M. adductor mandibulae externus profundus. In both

rallids (and in Aramus) the insertion is on M. adductor

mandibulae externus superficialis. In Rallus only, there is

an additional, more direct connection to the mandible.

Summary. This muscle in Aramus has some differences

from the corresponding muscle in both Balearica and








Grus, and some differences are found between the two cranes.

The insertion on M. adductor mandibulae medius is similar in

Balearica and Aramus, but in Grus it is on a different mus-

cle. The muscle shows some minor differences between the

two rallids, but in Fulica and Aramus the muscle agrees well.


16. M. pseudotemporalis

Rather pyramidal muscle with flat planes of anterior and

lateral faces oriented at right angles to each other distal

third comprised entirely of narrow, ossified tendon. Located

in anterior region of temporal fossa, posterior and ventral

to postorbital process, and in orbit, medial to postorbital

process. Attaches to temporal fossa, orbit, and to mandible.

Portion of origin from temporal fossa deep to M. adductor

mandibulae externus medialis and to posterior end of M. ad-

ductor mandibulae externus superficialis, although very small

portion of dorsal edge visible dorsal to latter muscle in

some specimens. Much of lateral face of muscle deep to belly

of M. pseudotemporalis bulbi. Distal end of muscle deep to

belly of M. adductor mandibulae externus superficialis and to

tendinous insertion of rostral part of M. adductor mandibulae

externus profundus. Tendon of insertion partly superficial

to, and partly enclosed by, medial part of M. adductor man-

dibulae medius.

Origin. Arises fleshily from anterodorsal corner of

temporal fossa, from medial surface of postorbital process,

and from area occupying about one-fourth of posterior wall of

orbit, just medial to postorbital process. Proximal end of





44

muscle covered by stzrng superficial fascia which adds ten-

dinous component to origin.

Insertion. Ossified tendon forms within belly near prox-

imal end of muscle and extends anteroventrad to become sole

insertion, attaching to medial aide of mandible onto tubercle

in posterior part of depression for insertion of M. adductor

mandibulae medius.

Action. Aids in closing mouth by adducting mandible.

Comparisons. In the Gruidae the origin from the tem-

poral fossa in Balearica is more extensive than in Grus (or

Aramus). In Balearica the inserting tendon bifurcates, and

one portion inserts on the fascia of M. adductor mandibulae

medium, while the other turns anteriorly and inserts on the

mandible. Grus resembles Aramus in having an undivided in-

serting tendon and in having the insertion independent and

entirely on the mandible. Both cranes differ from Aramus in

not having the inserting tendon penetrate the medial part of

M. adductor mandibulae medius.

In the Rallidae the origin from the temporal fossa is

lacking (present in Araus), and the orbital origin is larger

than in Aramus, occupying about half the posterior wall.

The two rallids differ from Aramus in having the inserting

tendon bifurcated, unossified, and not penetrating M. ad-

ductor mandibulae medium.

Sumnry. The Rallidae are distinct from the other two

families in having the origin arising almost entirely from

the orbit and in lacking the portion from the temporal fossa,

which is a large portion of the origin in the limpkin and is





45

the main origin in the cranes. Bifurcation in the inserting

tendon has perhaps arisen independently in Balearica and the

rails, since no such division occurs in Aramus or Grus.


17. M. pseudotemporalis bulbi

Small, strap-like muscle of soft texture and brownish

coloration. Located in anteroventral region of temporal

fossa aid posterolateral region of orbit. Attaches to cra-

nium, to muscle on posterior wall of orbit, and to connec-

tive tissue associated with lacrimal gland.

Ventral end deep to portions of M. adductor mandibulae

externus superficialis, M. adductor mandibulae externus

medialis, and lateral part of M. adductor mandibulae medius.

Middle of belly superficial to middle of lateral face of M.

pseudotemporalis.

Origin. Arises fleshily from narrow, small area of

cranium ventral to foramen ovale, just medial to dorsal edge

of quadrate.

Insertion. Muscle terminates, just medial to postorbi-

tal process, with fleshy attachment to posteroventral part of

lacrimal gland, by attachment of connective tissue fibers

onto muscle tissue superficial to anterior face of M. pseudo-

temporalis, and by attachment onto fascia covering postero-

ventral surface of eyeball.

Action. Uncertain; may pull on lacrimal gland and

thereby aid in discharging its secretions.

Comparisons. In the Gruidae, the origin in Balearica

is from the anterior edge of the temporal fossa, and in Grus






46

it arises from an area of the temporal fossa slightly dorsal

to that of Balearica (in Aramus it arises from a location

just anteroventral to the temporal fossa). In Balearica the

origin is posteroventral to the origin of M. pseudotemporalis,

but posterior to that origin in Grus (and ventral to it in

Aramus).

In the Rallidae this muscle is essentially the same as

in Aramus.

Summary. There is only a slight difference between the

two cranes in the location of the origin of this muscle, and

both are slightly different from Aramus. Otherwise the mus-

cle in the cranes is quite like thatof.Aramus, and in the

rallids the whole muscle is essentially the same as in the

limpkin.


18. M. pterygoideus ventralis

Large jaw muscle forming an elongate triangle with lar-

ger end posterior; divided except at insertion into super-

ficial and deep layers. Muscle covers all except dorsal

surface of posterior end of mandible and extends dorsad to

occupy region dorsal to buccal cavity. Attaches to mandi-

ble, to pterygoid, and to palatine.

The variability in the pterygoid muscles in closely re-

lated species was shown by Lakjer (1926) and is corroborated

in this study. Fisher and Goodman (1955) state that all

parts of their 4. pteryqoideus ventralis and M. pterygoideus

dorsalis may arise embryologically from a single muscle mass,

and some workers have synonymized all parts as components of





47

one muscle (Edgeworth, 1935, M. adductor mandibulae internus;

Gadow, 1893, Mm. pteryqoidei). From the similar orientation

of the bundles in Grus (Fisher and Goodman, 1955, fig. 7) it

seems more reasonable to include the lateral part of M.

pteryqoideus dorsalis with M. pterygoideus ventralis, and that

part is in fact fused with the adjacent part of M. ptery-

goideus ventralis in all the genera dissected in this study.

The classification of Fisher and Goodman is retained

here, for convenience, in spite of its artificial nature.

However, the terminology of the attachments is reversed,

since the pterygoids and palatines are more effectively

moved by contraction of these muscles than is the mandible.

Posterior end on both lateral and medial sides of man-

dible lies deep to muscle sheet composed of M. stylohyoideus

and M. constrictor colli, and portion along medial edge of

mandible deep to M. geniohyoideus. Posterior end contacts

edge of insertion of M. depressor mandibulae, and portion on

lateral side of mandible contacts posteroventral edge of in-

sertion of lateral part of M. adductor mandibulae medius.

Side of deep layer apparently fused to entire length of lat-

eral part of M. pterygoideus dorsalis. Superficial to in-

sertion of medial part of M. adductor mandibulae medius on

medial side of mandible. Deep layer superficial to medial

part of M. pterygoideus dorsalis and to M. protractor ptery-

goideus. Superficial layer superficial to all of deep layer

except a portion of lateral edge on ventral side.

Origin. Superficial layer arises partly fleshily and

partly by flattened, ossified tendon, from posteroventral





48

corner of lateral face of mandible. Additional fleshy and

tendinous origins arise from lateral, ventral, and medial

edges of posterior face of mandible. Portion of origin on

medial side of mandible common to both superficial and deep

layers. This origin is mostly fleshy but includes several

ossified tendons attaching to dorsomedial tip of internal

articular process.

Insertion. Superficial layer inserts fleshily on entire

ventrolateral trough of palatine, tendinously on ventral and

posterior edges of ventrolateral wing of palatine, and flesh-

ily on ventral surface of medial end of pterygoid. Deep

layer inserts fleshily on dorsolateral surface and ten-

dinously on dorsomedial edge of palatine.

Action. Retracts palatine and pterygoid and depresses

upper jaw.

Comparisons. In the Gruidae the deep layer in Balearica

(and Aramus) is simple, but in Grus it is further divided

into distinct lateral and medial parts. The superficial

layer in Grus is uniquely specialized in having a strong,

silvery aponeurosis over its insertion. In both cranes the

superficial layer is superficial to all of the deep layer

(to all but the lateral edge of the deep layer in Aramus).

In Balearica (and Aramus) the lateral surface of the deep

layer is completely fused to M. pterygoideus dorsalis but is

entirely separate in Grus. In Balearica (and Aramus) most of

the portion on the lateral surface of the mandible is covered

by M. stylohyoideus and M. constrictor colli, but very little






49

of this portion is covered by M. stylohyoideus and none by

M. constrictor colli in Grus. In Balearica the superficial

and deep layers are fused at the origins and along their

lateral edges (in Aramus the two layers are fused only at

their origins), but in Grus the two layers originate sep-

arately. Balearica (and Aramus) have a single insertion of

the superficial layer, but there are two separate insertions

in Grus. Balearica, and apparently Grus, differ from Aramus

in lacking ossified tendons in the origin.

In the Rallidae, the muscle in Rallus (and Aramus) is

composed of a superficial layer and a single deep layer, but

in Fulica the portion corresponding to the lateral part of

the deep layer of Grus is distinct, and the bundles corres-

ponding to the medial part of the deep layer are fused into

one muscle with the superficial layer.

In Fulica alone some of the muscle is deep to the ante-

rior, free portion of M. geniohyoideus, as a result of greater

thickness and more posterior attachment of that muscle.

Summary. For the details discussed above, Balearica

and Grus show little agreement, but Aramus and Balearica are

quite similar. The division in the deep layer in Grus repre-

sents the most striking specialization, and a somewhat simi-

lar specialization is present in Fulica. The muscle in Rallus

is quite like that of Aramus and differs from that of Fulica

mainly in the connections of the various portions.








19. M. pterygoideus dorsalis

Medium-sized and flattened muscle, oblanceolate in lat-

eral view; partially divided into dorsal and ventral divi-

sions. Located just anteromedial to angle of jaw. Attaches

to mandible, to pterygoid, and to palatine.

Lies deep to M. pteryqoideus ventralis. Adjoins poste-

rior edge of insertion of medial part of M. adductor mandibulae

medius and posterior edge contacts M. protractor pterygoideus.

Origin. Arises fleshily from wide area of medial and

dorsomedial part of mandible, between posterior edge of in-

sertion of M. adductor mandibulae medius and posterior edge

of mandible. Dorsomedial portion of origin occupied by

partially distinct dorsal section.

Insertion. Inserts tendinously and fleshily on all but

posterior surface of pterygoid. Partially separated dorsal

division inserts on posterior end of palatine, just anterior

to previous attachment.

Action. Depresses upper jaw by retracting palatine and

pterygoid.

Comparisons. In the Gruidae, the muscle in Balearica

(and Aramus) is simple, but in Grus it is comprised of dis-

tinct lateral and medial parts. The representative of the

lateral part in Balearica (and Aramus) is apparently com-

pletely fused into the lateral edge of the deep layer of M.

pterygoideus ventralis, and the medial part represents the

sole remnant of the muscle in this crane. In Balearica (and

Aramus) the muscle is partially divided into dorsal and





51

ventral sections, but no division occurs in the corresponding

part in Grus. In Balearica (and Aramus) the origin extends

from the medial onto the dorsomedial portion of the mandible,

but the corresponding part in Grus arises only from the medial

side. In Balearica (and Aramus), but not in Grus, a portion

of the insertion is on the dorsal side of the pterygoid.

In the Rallidae the muscle differs from that of Aramus

in having no evidence of the partial separation of the muscle

into dorsal and ventral sections and no attachment to the

palatine. In Rallus (and Aramus) the origin does not over-

lap the deep part of M. adductor mandibulae medius, but in

Fulica the origin is wider and overlaps the posterior edge

of the deep part of that muscle.

Summary. Grus seems specialized since the points by

which it differs from Balearica are strikingly alike in

Aramus and Balearica, and even like those in the two rallids.

Grus alone has a separate lateral part, and the partial di-

vision of the muscle in Aramus and Balearica is not found in

the corresponding, medial part in Grus. In Aramus and Rallus

the muscle is nearly identical, and differs only slightly in

Fulica.


20. M. protractor pterygoideus

Small muscle composed of sheet-like ventral part and

somewhat thicker dorsal part. Ventral part located poste-

rior to pterygoid; dorsal part located just posterodorsal to

pterygoid and posteroventral to orbital process of quadrate.

Attaches to basitemporal plate, to ventrolateral region of

orbit, and to pterygoid.






52

Anterior extent of ventral part in contact with M.

pteryqoideus dorsalis and partly deep to posterior edge of

M. pterygoideus ventralis. Dorsal part ventral to M. pro-

tractor quadratus.

Origin. Ventral part arises fleshily from anterolateral

area of basitemporal plate, adjacent to anterior edge of in-

sertion of medial part of M. rectus capitis ventralis. Dor-

sal part originates from lateral depression in basisphenoid

and from adjacent ventromedial area of orbit just antero-

medial to origin of M. protractor quadratus.

Insertion. Ventral sheet inserts fleshily along medial

edge of entire length of pterygoid bone. Dorsal sheet has

mostly fleshy insertion on posterodorsal side of posterior

end of pterygoid bone.

Action. Raises maxilla by pulling pterygoid forward.

Comparisons. In the Gruidae the muscle is composed of

only one part (definite dorsal and ventral parts in Aramus),

and the insertion is on the anterior third of the pterygoid

(on the full length of the pterygoid in Aramus).

In the Rallidae (as in Aramus) the muscle is in two dis-

tinct parts, and the ventral sheet inserts on the full length

of the pterygoid. In Rallus the dorsal part is enclosed by

fleshy fibers of M. protractor quadratus, but the same part

is ventral to that muscle in Fulica (and Aramus). In Rallus

the dorsal part is wide at its origin and inserts by a slender

but strong tendon. In Fulica (and Aramus) the origin of this

part is narrower, and the insertion is fleshy and wider.





53

Summary. The cranes are distinct from the limpkin and

the rails in having the muscle undivided, with a more re-

stricted insertion. Rallus appears specialized in having

the dorsal part enclosed, with a wide origin and a narrow and

tendinous insertion. In Aramus and Fulica the enclosure of

the dorsal part is lacking, the origin is narrower, and the

insertion is wider and fleshy.

The stronger insertion in Rallus may be associated with

feeding habits, such as gaping under pressure when the bill

is probed into mud, but a corresponding enlargement of M.

depressor mandibulae, as occurs in some passerines with strong

gaping adaptations (Beecher, 1951a), is lacking.


21. M. protractor quadratus

Small, thick muscle composed of very short fibers. Lo-

cated in small space between cranium and orbital process of

quadrate. Attaches to cranium and to quadrate.

Deep to belly of M. pseudotemporalis. Dorsal to lateral

portion of dorsal part of M. protractor pterygoideus, and

posterior to medial portion of same muscle.

Origin. Arises fleshily from area of cranium immediately

medial to orbital process of quadrate. Origin includes small

section of posteroventral region of orbit. Medial extend of

origin posterior to, and in contact with, medial extend of

origin of dorsal part of M. protractor pterygoideus.

Insertion. Has fleshy insertion on entire medial surface

of orbital process of quadrate.






54

Action. Raises maxilla by rotating lower end of quad-

rate forward.

Comparisons. In the Gruidae the origin in Balearica

(and Aramus) is larger and more ventrally located than in

Grus. The insertion in Balearica (and Aramus) is on all of

the medial surface of the orbital process of the quadrate,

but on only the posterior edge of the medial surface of that

process in Grus.

In the Rallidae the muscle in Rallus encloses the dorsal

part of M. protractor pterygoideus but is located entirely

dorsal to that muscle in Fulica (and Aramus).

Summary. The differences in the muscle in the two

cranes are very slight, but a closer resemblance between

Aramus and Balearica is apparent, in spite of the small dif-

ferences involved. Rallus appears more specialized in having

the muscle located farther ventrally than in Fulica or Aramus,

as a result of which is partially encloses another protractor

muscle.

This may also be associated with gaping adaptations,

since the muscle aids in opening the mouth by raising the

maxilla.


Muscles of the Hyoid


22. M. constrictor colli

Thin, partly double, dermo-osseous sheet with orienta-

tion of bundles anteromedial at anterior end, changing to

posteromedial and then to transverse along neck. Posterior






55

bundles loosely connected and gradually fade out posteriorly.

Extends from anterior end of basihyal bone posteriad across

throat, and lines skin of entire neck, nearly to posterior

end. Attaches to mandible, to connective tissue in mid-line,

to M. stylohyoideus, to M. dermo-temporalis, and to skin.

This muscle may include the posterior sheet of M. mylo-

hyoideus (also called M. serpio-hyoideus), which Fisher and

Goodman (1955) stated could not be found in Grus americana.

Fused to other member of pair by connective tissue in

mid-line. Extreme anterior end deep to M. intermandibularis.

Superficial on mandible to M. pterygoideus ventralis and to

hyoid and tracheal muscles in region of throat. Superficial

to posterior edge of M. dermo-temporalis and to M. tracheo-

hvoideus through most of length of neck.

Origin. Arises by two sheets that join at posteroven-

tral corner of mandible. One sheet attaches to superficial

and one to deep side of posterior edge of mandible. Deep

sheet arises in common with M. stylohyoideus, in contact with

insertion of M. depressor mandibulae. Both sheets superfi-

cial to origin of M. pterygoideus ventralis.

Insertion. In region of throat inserts on connective

tissue in mid-line and loosely onto skin. Posterior to man-

dible transverse bundles insert only on skin.

Action. Constricts and raises musculature of throat

and hyoid apparatus, and constricts skin on ventral side of

neck.

Comparisons. In the Gruidae the sheet is thinner than

in Aramus. In Balearica it has fewer contractile components






56

than in Aramus, and in Grus it has even fewer muscular fibers.

In Balearica the muscle arises by a deep fascial sheet and a

superficial muscular sheet, but in Grus only one sheet is

present (Aramus has two sheets, both muscular). In the cranes

only the superficial sheet contributes to the origin of M.

stylohyoideus (in Aramus both sheets contribute equally to

that origin). In both cranes the muscle lies between the

posterior end of the basihyal bone and the seventh cervical

(in Aramus it extends from the anterior end of the basihyal

nearly to the posterior end of the neck). In Balearica (and

Aramus) the muscle gradually fades into the skin posteriorly,

but in Grus it ends more abruptly on tracheal fascia and

cervical muscles.

In the Rallidae the contractile content of the muscle is

equal to that of Aramus, and in Fulica the thickness is even

greater. The division into two sheets is similar in both

rallids, but the inner one is weaker in Rallus. In Rallus

only the deep sheet, and in Fulica only the superficial sheet,

contributes to the origin of M. stylohyoideus. In both ral-

lids the bundles just posterior to the jaw pass further dor-

sad than in Aramus and even reach the mid-dorsal line in the

region of the frontal bones. In the two rails the anterior

end of the muscle is located more posteriorly than in Aramus,

lying about 5 mm posterior to the posterior end of the basi-

hyal bone. In both rallids the muscle ends on the skin of

the neck, but in Rallus it extends about half the length of

the neck, and in Fulica it extends the-full length.





57

Summary. This constrictor sheet is well developed in

Aramus and Rallus and is highly developed in Fulica. It is

reduced in the cranes, especially in Grus. The deep sheet

of the origin is better developed in Aramus than in the ral-

lids and entirely lacks contractile fibers in the gruids.

In the limpkin the anterior end of the muscle is anterior to

the position in the cranes and considerably anterior to that

in the two rallids. In the cranes the muscle sheet barely

extends onto the neck, but covers at least half the neck in

the other three genera. This constrictor sheet appears to

have been variously modified in the species studied, but in

extent and development the muscle in Aramus finds somewhat

better agreement in the rallids than in the gruids.


23. M. intermandibularis

Thin muscle sheet with bundles oriented essentially

transversely and gradually becoming indistinct at anterior

end. Located between rami of mandible. Attaches to mandible,

to connective tissue in mid-line, and loosely to skin.

Fused to other member of pair by connective tissue in

mid-line. Posterolateral edge deep to anterior end of M.

geniohyoideus. Superficial to M. genioglossus, and posterior

end superficial to anterior ends of M. constrictor colli and

M. stylohyoideus.

Origin. Takes fleshy origin from dorsomedial edge of

mandible on line extending from gonys to about level of mid-

dle of basihyal bone.






58

Insertion. Inserts in mid-line on same connective tis-

sue to which M. constrictor colli attaches, on line extending

posteriad from gonys to point 10 mm beyond posterior end of

basihyal bone.

Action. Raises anterior hyoid musculature and floor of

mouth.

Comparisons. In the Gruidae the muscle is quite reduced,

being composed of a very thin contractile sheet in Balearica

and having only a few muscular fibers in Grus (in Aramus the

entire sheet is muscular and thicker). In Balearica contrac-

tile fibers are indistinct in the anterior half of the bill

and in Grus are not present at all except at the posterior

end of the sheet. In Balearica the posterior end of the ori-

gin is slightly anterior to that of Aramus, but the posterior

end of the insertion is considerably posterior to that point

in Aramus, being about even with the posterior end of the

basihyal bone.

In the Rallidae the thickness and contractile nature of

the muscle agrees with that of Aramus, but the muscle is

thicker in Fulica. In both rallids the muscle sheet becomes

thinner, with its anterior regions more closely attached to

the skin than in Aramus. In both rallids the posterior ends

of the origin and the insertion are located slightly posterior

to the corresponding locations in Aramus.

Summary. This muscle is quite reduced in the gruids,

especially so in Grus. It is well developed in Aramus and

the rallids, especially in Fulica. The position of the poste-

rior edge of the muscle in Aramus is intermediate between






59

that of the cranes and that of the rails. In Aramus and the

gruids the anterior end of the sheet is more closely attached

to skin than in the rallids. The differential development of

this muscle in the three families is parallel to that of M.

constrictor colli, and as is found in the latter muscle,

Aramus agrees better with the rallids than with the gruids.


24. M. geniohyoideus

Very elongate, thin band of muscle. Located mainly be-

neath floor of mouth along medial side of mandible, but ex-

tends posteriad around posteroventral corner of mandible to

lie along posterolateral edge of cranium. Attaches to man-

dible, to floor of mouth, and to thyrohyals.

Middle of belly deep to M. constrictor colli, and pos-

terodorsal tip deep to M. dermo-temporalis. Anterior half

superficial to lateral edge of M. intermandibularis, and mid-

dle of belly superficial to ventral side of M. pterygoideus

ventralis. Posterior portion superficial to portion of M.

ceratoglossus, and posterodorsal portion passes over YF.

rectus capitis ventralis and M. rectus capitis lateralis.

Origin. Arises fleshily from elongate area along dorso-

medial side of ramus of mandible. Extends from level of

posterior end of mandibular foramen to about level of anterior

half of nostril, lying just ventral to origin of M. inter-

mandibularis. Posterior end of attachment lies between M.

pterygoideus ventralis and mandible.

Insertion. Posterior end passes onto greater cornu of

hyoid, partially encloses ceratohyal, attaches loosely to





60

posterior end of that bone and to anterior end of epihyal,

and finally inserts fleshily onto entire surface of poste-

rior end of epihyal and its cartilaginous extension.

According to Fisher and Goodman (1955) the mandibular

attachment is the insertion, and the thyrohyal attachment is

the origin. Since the latter attachment is the more movable,

it is considered here as the insertion and the mandibular

attachment as the origin.

Action. Protracts tongue by pulling hyoid apparatus

forward.

Comparisons. In the Gruidae, Balearica is unique in

having an additional small lateral slip that arises from the

lateral face of the mandible. The gruids differ from Aramus

in having the muscle connect to M. dermoalossus. but this un-

ion is inconstant in Grua. In Balearica the origin of the

main slip is long and extends slightly farther anteriorly

than in Aramus, but in Grus this attachment (called inser-

tion by Fisher and Goodman, 1955) is much shorter. In

Balearica (and Aramus) the posterior end encloses the cerato-

hyal but attaches only loosely to the posterior end. In

Grus this attachment is more extensive, as is the epihyal

attachment (called origin by Fisher and Goodman, 1955). The

small lateral slip, present only in Balearica, fuses with

the main slip at the side of the distal end of the insertion.

The individual variation mentioned for this muscle in Grus

is not found in Aramus.

In the Rallidae a small lateral slip is found in Rallus

but not in Fulica. Both rallids agree with Aramus in lacking






61

connection of the muscle to M. dermoglossus. The combined

origin of the two slips, from the lateral face of the man-

dible, is short and deep in Rallus and corresponds to the

origin of the single slip in Fulica (in Aramus a single ori-

gin is also present, but it is very much longer and shal-

lower and comes from the medial side of the mandible). In

both rallids the enclosure of the ceratohyal and the inser-

tion on the epihyal are both similar to conditions in Aramus.

The small slip in Rallus fuses with the posterir end of the

insertion of the main slip.

Summary. This muscle agrees in the cranes and the

limpkin in having a rather long, shallow origin, whereas in

the rallids the origin is very short but deep. It seems

that the more anterior extension would allow greater protrac-

tion of the tongue in the cranes and the limpkin. The divi-

sion into two slips seems to have arisen independently, but

strikingly similarly, in Balearica and Rallus. The small

lateral slip could act to pull the distal end of the cornu

laterad and perhaps to brace the protracted tongue.


25. M. stylohyoideus

Very long, narrow group of bundles arising as anterodor-

sal edge of sheet of M. constrictor colli. Located in ventro-

lateral region of throat. Attaches to mandible, to M. con-

strictor colli, and to entoglossum.

Anterior end deep to M. constrictor colli, M. interman-

dibularis and M. genioqlossus. Posterior end fused with both

sheets of M. constrictor colli, and anterior half lies






62

alongside M. ceratoglossus lateralis. Posterior end super-

ficial to posterior end of M. ceratoglossus inferior and to

M. pterygoideus ventralis. Middle of belly passes over M.

geniohyoideus.

Origin. Arises as part of both sheets of M. constrictor

colli, from dorsomedial and dorsolateral corners of posterior

edge of mandible.

Insertion. Separates from M. constrictor colli as it

passes under ventral edge of mandible and follows side of M.

ceratoglossus lateralis to insert fleshily on tendon of that

muscle and on posterolateral corner of entoglossum.

Action. One muscle turns tongue laterad, but both to-

gether retract tongue and perhaps raise it.

Comparisons. In the Gruidae the muscle in Balearica is

much thinner and flatter than in Grus (or Aramus). In

Balearica the origin merges imperceptibly with M. constrictor

colli, but in Grus (and Aramus) it appears as separate mus-

cle. In both cranes the muscle agrees with that of Aramus

in arising partly from the mandible, but differs in having

no origin from the medial side. Grus is unique in having a

portion arise from the opisthotic process. In Balearica a

part of the insertion (and all of the insertion in Aramus)

is on the posterolateral corner of the entoglossum, but the

remainder of the insertion in Balearica is on the dorsolat-

eral portion of the anterior end of the basihyal. In Grus

the insertion is on the most anterolateral surface of the

ceratohyal, at the articulation between that bone and the





63

basihyal. The more posterior location of the insertion in

Grus would result in less effective movement of the tongue,

so that the main function in this genus is apparently re-

traction of the hyoid apparatus.

In the Rallidae the muscle in Rallus is small and band-

like as in Aramus, but in Fulica it is very thick and some-

what rectangular in cross section. In Rallus (and Aramus)

the muscle originates partly from both sheets of M. constric-

Ia colli, but no connection with that muscle is present in

Fulica, in which the origin is entirely from the side of the

posterior end of the mandible. In Rallus the anterior end

of the muscle is variable but usually divides into two por-

tions, one inserting on the anteromedial extent of the

ceratohyal and the other usually inserting on the dorsal side

of the posterior portion of the basihyal bone, although this

anterior insertion is sometimes on the ceratohyal, just an-

terior to the previous one. In Fulica the bundles of the

anterior end of the ceratohyal and the posterior end and lat-

eral side of the basihyal (in Aramus it inserts on the ento-

glossum). In both rallids the action is probably retraction

of the whole hyoid, rather than direct movement of the tongue

as in Aramus. The larger muscle in Fulica indicates a strong-

er action.

Summary. This muscle is variable and apparently quite

subject to specialization among the genera studied. The

shape and size of the belly are nearly uniform in the genera

other than Fulica, in which the muscle is considerably larger.







The origin is from both lateral and medial faces of the man-

dible in the limpkin and in Rallus, but arises only from the

side in Fulica and the gruids. The variable insertion is

similarly located in Aramus and Balearica, but it is much

farther posterior in Grus and the rallids. In view of the

more anterior insertion, it seems that the main function in

Aramus and Balearica is to move the tongue laterad and raise

it, but in Grus and the rallids it must retract the hyoid

apparatus.


26. M. genioglossus

This muscle sheet is not present in Aramus, and no con-

tractile fibers are found in the membranous floor of the

mouth. M. intermandibularis, largely absent or reduced to

fascia in Grus, is well developed in Aramus and lies just

superficial to the presumed location of M. genioglossus.

The former sheet has an origin similar to that described for

the latter muscle, but its insertion is not on the floor of

the mouth or the entoglossum, and therefore it is an entirely

different muscle, even though it probably has a somewhat

similar function.

Comparisons. In the Gruidae, the muscle is absent in

Balearica but present in Grus. In Grus the muscle is a thick,

widely triangular sheet, the lateral edge of which lies be-

tween M. geniohyoideus and the floor of the mouth. It arises

from a small area on the inner side of the mandible, dorsal

to the insertion of M. geniohyoideus, and flares widely to

insert on the floor of the mouth and on the posterior half





65

of the entoglossum. The anterior ends of the corresponding

right and left muscles meet in the mid-line of the ento-

glossum. The apparent function of the two muscles is to

raise the tongue and floor of the mouth, although one muscle

alone could turn the tongue laterad.

The absence of the muscle in Balearica, compared to the

presence in Grus, may be correlated with the more anterior

insertion of M. stylohyoideus, for lateral movement of the

tongue, in Balearica (and Aramus). In Grus that insertion

is considerably posterior to the tongue, but a similar func-

tion is apparently served in that crane by M. genioglossus.

In the Rallidae the muscle is absent in Rallus but well

developed in Fulica. In Fulica the origin extends along all

but the anterior end of the dorsomedial edge of the mandibu-

lar ramus, just dorsal to the origin of M. intermandibularis.

The insertion is on the floor of the mouth and the base of the

entoglossum.

Summary. The muscle is absent in Aramus, Balearica,

and Rallus but is well developed in Grus and even more so in

Fulica. Its absence in Aramus and Balearica may be func-

tionally correlated with an insertion of M. stylohyoideus

much farther anterior than in Grus. This correlation is not

apparent in the two rallids, even though the insertion of M.

stylohyoideus is usually anterior to that of Grus. This mus-

cle is apparently modified in association with specialized

feeding habits. The well-developed condition, at least in

Fulica, is probably associated with pressing the tongue






66

against the papillae in the roof of the mouth in order to

grasp vegetation.


27. M. dermoglossus

This muscle is absent in Aramus.

Comparisons. In the Gruidae the muscle is present. In

Balearica and Grus it is a short, thin sheet arising from the

basihyal bone. In Balearica the origin is from the lateral

face of the middle of the bone but from the dorsolateral

corner of the anterior end in Grus. The insertion in both

cranes is on the wall of the pharynx, but in Balearica it

also merges with M. constrictor colli and is joined by the

small sheet of the posterior part of M. ceratoglossus in-

ferior, arising from the middle of the ceratohyal. Contrac-

tion of the muscle would draw the lateral pharyngeal walls

forward, perhaps during swallowing.

According to Fisher and Goodman the muscle arises from

the pharynx and inserts on the basihyal. Since the pharyn-

geal attachment is the more movable, the origin and inser-

tion should be reversed, as they are described above.

In the Rallidae the muscle is absent.

Summary. The muscle is present in Gruidae, but in

Aramus and Rallidae it is absent.


28a. M. ceratoglossus lateralis

Very elongate and somewhat rounded. Located on lateral

and dorsal aspects of hyoid apparatus, from middle of cornu

to base of entoglossum. Attaches to ceratohyal, loosely to






67

basihyal, to M. stylohyoideus, to M. hypoglossus rectus, and

to entoglossum.

Posterior tip deep to posterior end of M. ceratoglossus

inferior and also to part of M. geniohyoideus. Most of mus-

cle lies deep to sheets of M. constrictor colli and M. inter-

mandibularis. Courses alongside M. hypoglossus obliquus and

M. hypoglossus rectus. Lies medial to insertion of M. stylo-

hvoideus. Located superficial to combined bellies of M.

thyroglossus and M. thyrohyoideus.

Origin. Arises fleshily from dorsal and lateral sur-

faces of anterior two-thirds of ceratohyal, and attaches

loosely to side of basihyal.

Insertion. Alongside M. hypoglossus obliquus belly

narrows into small tendon that continues anteriad to receive

portion of insertion of M. stylohyoideus, to attach to side

of M. hypoglossus rectus, and finally to merge with postero-

lateral region of entoglossum.

Action. One muscle bends tongue ventrolaterad, and

both together pull tongue downward.

Comparisons. In the Gruidae the muscle is superficial

to the posterior end of the posterior part of M. ceratoglossus

inferior, instead of deep to it as in Aramus. In Balearica

(and Aramus) the muscle arises from the dorsal and lateral

surfaces of the ceratohyal, but in Grus it arises from the

ventrolateral and dorsolateral surfaces. In both cranes (and

Aramus) the origin is from the anterior two-thirds of the

ceratohyal. The points of insertion in both gruids agree






68

with those of Aramus, but in Balearica (and Aramus) attach-

ment is by a tendon, and in Grus the muscle is fleshy

throughout.

In the Rallidae the origin is from all but the ventral

surface of the full length of the ceratohyal bone (in Aramus

it arises from the dorsal and lateral surfaces of the anterior

two-thirds). In both rallids the small tendon begins at

about the middle of the belly and lies superficially on the

belly (in Aramus the tendon arises much farther forward, at

the anterior end of the belly). The insertion in both ral-

lids is essentially the same as in Aramus. In Fulica (and

Aramus) the inserting tendon receives part of the insertion

of M. stylohyoideus, but no such connection exists in Rallus.

Summary. Aramus differs from the rallids but resembles

the gruids in having a smaller area of origin and a shorter

tendon of insertion. However, Grus is unique among the genera

examined in having the insertion entirely fleshy.


28b. M. ceratoolossus inferior

Rather short band of muscle. Lies against ventral side

of hyoid musculature between posterior ends of mandibular

rami. Attaches to ceratohyal and to connective tissue in

mid-line.

The single slip in Aramus corresponds to the posterior

part in Grus, but the lateral and medial parts found in that

crane are lacking in the limpkin.

Muscle lies entirely deep to M. constrictor colli, and

posterior end also deep to M. geniohyoideus. Lies






69

superficial to M. ceratoqlossus lateralis on ceratohyal, and

belly lies superficial to M. thyroqlossus and M. thyrohyoideus.

Origin. Arises fleshily from ventral surface of cerato-

hyal, beneath M. geniohyoideus, from line of origin about as

long as width of muscle.

Insertion. Inserts in ventral mid-line, deep to area of

overlap of, and on connective tissue that forms insertion of,

M. constrictor colli and M. intermandibularis.

Action. May act to raise or protract hyoid apparatus,

or both.

cnmp~rrinnn. In the Gruidae, alearica agrees with

Aramnia in having the muscle represented by only the posterior

part, which is a band-like sheet. In Grus the muscle in-

cludes lateral and medial parts, and the posterior part is

more elongate and rounded. In rus both the lateral and

medial parts arise from the anterior end of the ceratohyal,

and the lateral part inserts on H. hvyoclossus rectua and on

the ventrolateral corner of the entoglossum, while the medial

part inserts on the middle of the basihyal. In Balearica

the sole (posterior) part arises from the entire surface of

the posterior one-third of the ceratohyal (in Aramus it arises

from a line about the width of the muscle), but in Grus the

corresponding origin is apparently much smaller. The inser-

tion of the posterior part in Balearica (and Aramus) is on

connective tissue in the ventral mid-line, but in Grus it is

on fascia over the junction of the basihyal and urohyal.





70

In the Rallidae the muscle is somewhat thicker in Fulica

than in Rallus (or Aramus). Points of attachment agree in

the rails and the limpkin.

Summary. The muscle differs only in thickness and ex-

tent of origin in the genera other than Grus, but in that

crane it includes two additional parts. The one part common

to all genera inserts in Grus in an entirely different loca-

tion from that of Balearica and the non-gruids. In Aramus,

Balearica, and the two rallids the muscle apparently func-

tions in raising the hyoid apparatus and perhaps in protract-

ing it, but in Grus the only apparent function is to adduct

the cornua of the hyoid.


29. M. hypoglossus rectus

Small, triangular muscle with attenuate anterior end.

Closely fused with opposite member in mid-line, and two mus-

cles have common tendon anteriorly. Occupies ventral face

of posterior end of entoglossum and median strip along ven-

tral surface of tongue. Attaches to entoglossum and to M.

ceratoqlossus lateralis.

Right and left muscles loosely connected across mid-

line. Completely deep to M. intermandibularis. Posterior

end adjacent to insertions of M. stylohyoideus and M.

ceratoglossus lateralis.

Origin. Arises fleshily from general face of posterior

end of entoglossum, and to lesser extent, from inserting ten-

don of M. ceratoglossus lateralis.






71

Insertion. Right and left muscles have common insertion,

by narrow and strap-like tendon that extends along ventral

mid-line of tongue and attaches onto ventral side of anterior

portion of entoglossum.

Action. Causes tongue to curve downward.

Comparisons. In the Gruidae the muscle has fewer fleshy

fibers and more extensive tendons that in Aramus. In

Balearica (and Aramus) the main origin comes from the ento-

glossum, with a lesser origin from M. ceratoglossus lateralis,

but in Grus it arises mainly from the lateral part of M.

ceratoglossus inferior, which is lacking in Balearica (and

Aramus). In Grus the inserting tendon connects to M. genio-

glossus, which is also absent in Balearica (and Aramus).

The length of the inserting tendon varies with the length of

the tongue in the two cranes and the limpkin.

In the Rallidae the muscle differs from that of Aramus

in being slightly longer and narrower, with closer connection

to the inserting tendon of M. ceratoglossus lateralis. The

actual size of the belly is similar in both rallids in spite

of differences in the length of the tongue, but the tendon

is longer in Rallus. In Fulica only, the paired bellies do

not contact across the mid-line.

Summary. The pattern of the muscle is rather constant

in all genera studied, even though the length and shape of

the tongue vary considerably. Differences in the length of

the tongue are reflected in differences in the length of the

tendon of insertion. In Grus the muscle connects to two mus-

cles not present in the other genera.








30. M. hypoglossus obliquus

small, triangular muscle with lateral and ventral faces

at right angles to each other. Located on lateral and ven-

tral faces of anterior end of basihyal. Attaches to basi-

hyal and to entoglossum.

Right and left muscles loosely fused across mid-line.

Entirely deep to M. intermandibularis. Lies just medial to

anterior portion of M. ceratoglossus lateralis, ventromedial

to insertion of M. stylohyoideus. and just posterior to M.

ceratoglossus inferior.

Origin. Arises fleshily from lateral and medial faces

of anterior half of basihyal.

Insertion. Attaches fleshily to ventral and lateral

edges of posterior end of entoglossum, adjacent to posterior

edges origin of M. hypoglossus rectus.

Action. One muscle pulls tongue ventrolaterad, but both

muscles together depress distal portions of tongue.

Comparisons. In the Gruidae the muscle in Balearica is

thinner than in Grus (or Aramus), but it lies along the full

length of the ventral side of the basihyal instead of only

the anterior two-thirds as in Grus (or the anterior half as

in Aramus). In Grus the muscle is deep to the anterior ten-

don of the lateral part of M. ceratoglossus inferior and M.

genioglossus, and lies medial and superficial to the medial

part of M. ceratoglossus inferior; none of these muscles are

present in Balearica (or Aramus). The origin is more exten-

sive in Balearica than in Grus (or Aramus). Grus is unique






73

in having some tendinous components to the origin. In

Balearica (and Aramns) the insertion is on the ventral and

lateral edges of the posterior end of the entoglossum, but

in Grus the insertion is narrower, on only the ventrolateral

corner of the entoglossum. In Balearica only, the insertion

is partly on the medial side of the inserting tendon of M.

ceratoglossus lateralis.

In the Rallidae the muscle is larger in Rallus than in

Fulica (or Aramus), but the shortened basihyal in the coot

makes comparison difficult. In Rallus the muscle occupies

the full length of the basihyal, but in Fulica it does not

cover the posterior end (in Aramus it covers only the ante-

rior end). The rallids differ from Aramus in having the mus-

cle attach to the medial side of the inserting tendon of M.

ceratoqlossus lateralisy this attachment is stronger in

Fulica.

Summary. The size and attachments of the muscle are

varied among the genera studied, and there seems to be no good

correlation with the length of the tongue. The muscle is

longest in Balearica and Rallus, but the tongue is short in

the former and long in the latter. The muscle is shortest

in Aramus, which has the longest tongue, and Fulica, which

has a short tongue. However, the two genera with the shortest

tongues, Balearica and Pulica, both have close connection of

the muscle to the tendon of M. ceratoglossus lateralis along-

side it. Such connection is very weak or lacking in the

other three genera, all of which have long tongues. This






74

muscle is certainly more subject to specialization than is

M. hypoglossus rectus.


31. M. thyroqlossus
32. M. thyrohyoideus

Long and somewhat rounded, composed of two inseparable

muscles, lateral M. thyrohyoideus and medial M. thyroglossus.

Very narrow, entirely separate accessory slip of former muscle

lies lateral to main belly. Located in ventral region of

pharynx, between hyoid apparatus and larynx. Attaches to

larynx, to wall of pharynx, to basihyal, to entoglossum, to

urohyal, and to ceratohyal.

Muscles on each side loosely connected across mid-line.

Posterior half partly deep to M. constrictor colli, M. inter-

mandibularis, and posterior part of M. ceratoglossus inferior;

anterior portion partly deep to M. ceratoglossus lateralis and

M. stylohyoideus.

Origin. Main belly arises fleshily from lateral and

ventral regions of anterolateral portion of cricoid cartilage,

adjacent to lateral edges of M. thyroarytenoideus and M.

constrictor glottidis. Small portion originates from ventro-

lateral wall of pharynx, posterior to attachment to cricoid,

more or less continuous with portion of insertion of M.

tracheohyoideus in same area. Small accessory part of M.

thyrohyoideus arises separately from ventrolateral wall of

pharynx.

Insertion. Belly passes dorsal to basihyal, where

small fasciculi partially separate from main belly. One


~






75

fasciculus inserts on dorsolateral edge of basihyal about 2 mm

anterior to posterior end of bone. Other fasciculi remain

partially joined and insert fleshily on all of dorsal sur-

face of anterior third of basihyal and on entire posteroven-

tral edge of entoglossum. Separate accessory part of M.

thyrohyoideus inserts on junction of urohyal, basihyal, and

ceratohyal.

Action. Muscles on one side reflect tongue dorsolat-

erad. Both sides together raise distal portions of tongue,

retract hyoid apparatus, and protract larynx.

comparison. In the Gruidae the main origin is from the

posterior edge of the cricoid cartilage (in AramraL it arises

from the anterolateral portion). The cranes differ from

ran a=s in having the accessory part arise partly from the cri-

coid. In nl-iar.n (and Aramus) the muscle Partially divides

into fasciculi in the region dorsal to the basihyal, but it

remains as a compact mass in Grus. In Ralearica (and Aramus)

the muscle inserts on the dorsal surface of the basihyal but

inserts on the lateral surface in Gurs. In Baleari.c~ (and

Aramus), but not in G-1s, a small fasciculus parts from the

main muscle to insert on the posterior region of the basihyal.

In both cranes the accessory part fuses with the main muscle

instead of inserting separately as in Aramus.

In the Rallidae the two muscles under discussion differ

from those of Aramus in being separate and in lacking the

accessory part, In both rallids M. thyroglossus is wide

posteriorly and narrow anteriorly, but in Fulica the change

from wide to narrow is more abrupt. Sometimes in Rallus






76

(and always in Aramus the right and left Mm. thyroglossi are

loosely connected across the mid-line and lie superficial to

the medial edges of Mm. thvrohvoidei. In Fulica the two Mm.

thyroglossi are closely connected across the mid-line and lie

superficial to all but the posterolateral portions of Mm.

thyrohoidei. In both rallids M. thyroglossus arises mainly

from the posterior region of the cricoid (in Aramus it arises

from the anteroventral edge), and M. thyrohyoideus arises

from the ventrolateral region of the full length of the larynx

(from the anterolateral region in Aramus). In both rallids

M. thyroqlossus is short, inserting on the junction of the

basihyal, ceratohyal, and urohyal bones (in Aramus the main

muscle is farther anterior, but the above insertion is simi-

lar to that of the accessory part of M. thyrohoideus). In

Rallus M. thyrohyoideus inserts on the dorsal face of the

anterior portion of the basihyal (corresponds to the main

insertion of the combined muscle in Aramus), but in Fulica

this insertion is on most of the dorsal face of the basihyal.

Summary. The cranes and the limpkin are quite distinct

from the rallids in having the two muscles inseparably fused

and in having an accessory part. In the rallids the two

muscles are quite distinct from each other and are of dif-

ferent lengths. For minor variations, Aramus and Balearica

show almost as many points of agreement as do Balearica and

Grus. Aramus is unique in having these muscles insert on

the entoglossum. The two muscles are apparently good famil-

ial indicators, since some unique differences occur in each

family.








33. M. tracheohyoideus

Narrow and very elongate dermo-osseus muscle, compact

in anterior and posterior regions but quite flattened in mid-

dle of belly. Forms part of wider sheet of muscle in poste-

rior region of neck. Located on ventrolateral side of full

length of neck, between trachea and skin. Attaches to larynx,

to trachea, to skin, to M. dermo-temporalis, and to furculum.

Deep to M. constrictor colli throughout at least ante-

rior two-thirds of neck. Adjacent to ventromedial edge of M.

tracheohyoideus and fused with same in posterior half of neck.

Origin. Arises fleshily from most ventral edge of fur-

culum, just lateral to mid-line. Originates as ventromedial

portion of common sheet formed by its fusion with M. dermo-

temporalis, but separates from ventral edge that muscle in

about middle of length of neck.

Insertion. Inserts on skin throughout posterior half of

length of belly, and attaches strongly to ventrolateral por-

tion of trachea near anterior end. Main insertion (which might

be considered as anterior origin) fleshy, mainly on postero-

lateral extent of cricoid, just posterior to insertion of

M. tracheohyoideus. Small slip diverges near anterior end

and further divides into smaller slips, some of which insert

on ventrolateral portion of most anterior extent of trachea,

and some of which attach to ventrolateral region of pharynx.

Latter slips more or less continuous with portion of origin

of M. thyrohyoideus in same area.

Action. Acts mainly with M. dermo-temporalis as flexor

of skin of neck, but may also retract trachea.






78
Comparisons. In the Gruidae the muscle in Balearica

(and Aramnsa extends from the furculum to the larynx, but in

Grus it occupies only the anterior third of the neck. In

Balearica (and Aramus) it arises fleshily from the furculum,

but in Grus it arises from the skin and from fascia between

the trachea and the vertebral column, about 14 cm from the

anterior end of the neck. In Balearica the muscle is con-

siderably thinner than in Aramus; the comparison is not

available for Grus. In Balearica the origin is from the full

width of the anterior face of the ventromedial portion of the

furculum (only from the ventromedial edge in Aramus), and the

posterior portion of the belly is indefinably fused with M.

dermo-temporalis (fused but still traceable in Aramus). In

Grus the muscle is not present in this portion of the neck.

In both cranes the muscle attaches to the anterior third of

the trachea (only to the anterior end in Aramus). In Balearica

(and Aramus) the main insertion is on the side of the poste-

rior edge of the cricoid, but in Grus it is on the ventral,

lateral, and dorsal surfaces of the posterior end of that

cartilage. The cranes agree with Aramus in having a small,

divergent slip form a portion of the insertion. This inser-

tion is compact in the gruids, on the wall of the pharynx

and the dorsal surface of the cricoid in Balearica, and on

the arytenoid in Grus (in Aramus the slip diverges into a

variable number of smaller ones that attach to the trachea

and pharynx).

In the Rallidae the muscle in pallus agrees with that of

Aramus in dividing into a main portion and a small slip, but






79

in Fulica it is not divided. In both rallids the origin from

M. dermo-temporalis is like that of Aramus. In Rallus the

main origin comes from the sternoclavicular ligament and the

anteroventral corner of the keel of the sternum, ventral to

the bundles of M. dermo-temporalis. In Fulica it arises

mainly from the sternoclavicular ligament, dorsal to the

bundles of M. dermo-temporalis, but it soon crosses deep to

that muscle to assume the usual position along the ventro-

medial edge (in Aramus this origin is from the furculum).

In Rallus (and in Aramus) it remains fused with M. dermo-

temporalis through its posterior half, but in Fulica it is

fused only at the origin. In Rallus there is very little

attachment to the trachea anteriorly, but in Fulica (and

Aramus) it attaches for about the anterior third of its

length and has strong attachment to the dorsal side of the

trachea for a distance of about one cm. In Rallus (and

Aramus) the main portion inserts on the side of the poste-

rior end of the cricoid, and the small slip inserts on the

dorsal side of the larynx (and also on the pharynx in Aramus).

In Fulica there is no division, and the anterior end of the

muscle inserts as a single unit on the lateral and dorsal

sides of the posterior edge of the larynx.

Summary. In Grus the muscle is much shorter than in the

other genera, and the condition corresponds well with that

described by Fisher and Goodman (1955) for M. dermo-

temporalis in this crane. The reduction indicates a general

decrease in the movability of the cervical skin in Grus.






80
Variations occur between the members of the Gruidae and the

Rallidae in both posterior and anterior attachments. Aramus

is unique in having the most anterior portion of the inser-

tion divided into several small slips.


34. M. tracheolaryngeus superior
35. M. tracheolarynqeus inferior

single, elongate band of muscle, wide and thin in ante-

rior portion and more compactly narrow in posterior three-

fourths. Posterior extent divided into two slips. Thinner

portion covers ventral surfaces of larynx and anterior 2.5 cm

of trachea. Narrower portion continues from that point along

side of trachea to syrinx.

Fisher and Goodman (1955) found this muscle in two parts,

superior and inferior, which they described as separate mus-

cles.

At anterior end medial edges of right and left sheets

nearly in contact at mid-line. Lies deep to M. constrictor

colli and M. tracheohyoideus throughout most of length of

neck. Posteriorly, two slips pass on either side of inser-

tion of M. sternotrachealis.

Origin. Since this muscle does not attach to bone, and

is attached to movable structures at both ends, it is not

possible to designate a trenchant origin or insertion. It

seems most reasonable to regard both the laryngeal and

bronchial attachments as origins and the entire intervening

tracheal attachment as the insertion: that interpretation is

followed here.








Anterior origin (listed as insertion of M. tracheolaryn-

geus superior in Fisher and Goodman, 1955, and origin of M.

tracheo-lateralis by Miskimen, 1951) arises from full length

and most of width of cricoid cartilage of larynx. Posterior

origin (comparable to insertion of M. tracheolaryngeus infe-

rior of Fisher and Goodman, and to insertion of M. tracheo-

lateralis in Miskimen) arises partly from most anterior

syringeal cartilage. From this point muscle immediately di-

vides into two slips that rejoin at another portion of origin,

just anterior to insertion of M. sternotrachealis; one slip

may give off tiny fasciculus to previous muscle.

Insertion. Wider anterior end attaches loosely to most

of ventral surface of trachea, but soon narrows and moves

laterad to insert loosely on narrow area along side of re-

mainder of length of trachea.

Action. Shortens trachea by drawing together cartilag-

inous rings but probably also retracts larynx and protracts

syrinx and bronchus.

Comparisons. The condition of the muscle in the limpkin

is closely approached in some passerines, according to

Miskimen's descriptions. However, she gives the laryngeal

attachment as the origin and states that the muscle divides

at its attachment to the anterior end of the syrinx to form

Mm. broncho-trachealis anticus and posticus, which insert on

the anterior end of the bronchus. The latter two seem to

represent separate muscles that are equivalent to the two

slips of the posterior end of M. tracheolaryngeus in Aramus.






82

In the Gruidae the muscle in Balearica agrees with the

single condition in Aramus, but in Grus it is divided into

superior and inferior parts, both of variable length. The

inferior part in Grus is narrower and much longer than the

corresponding portion in Balearica (or Aramus) because of the

extra length of the coiled trachea. The anterior origin in

Balearica and Grus is restricted to the medial portion of the

ventral edge of the cricoid (in Aramus it arises from most of

the ventral surface and the full width of the posterior edge

of the cartilage). In Balearica the posterior origin is by

a single tendinous band that extends anteriorly about half-

way to the insertion of M. sternotrachealis (as previously

noted by Beddard, 1898). In Grus this tendon is very short

(in Aramus the muscle arises, essentially fleshily, from the

syrinx by two heads that eventually fuse). In Balearica (and

Aramus) the anterior portion of the muscle is wide and at-

tached to the ventral surface of the trachea, but in Grus

this portion is narrower and apparently attached mainly at

the posterior end of the superior part. In the two cranes

the muscle receives the insertion of M. sternotrachealis,

but in Aramus the muscle divides and passes on either side

of the insertion of M. sternotrachealis.

In the Rallidae the muscle is somewhat larger than in

Aramus. In Fulica alone, it is very highly developed, form-

ing a continuous sheet from the dorsal to the ventral mid-

line in the anterior and posterior portions of the trachea.

There is even some overlap of the muscles from the two sides








on the dorsal surface of the posterior portion of the tra-

chea, and the muscle extends farther anteriorly on the side

of the trachea than in Rallus (or Aramus). In all three

specimens of Rallus the muscle on the left side divides poste-

riorly into three branches. The first of these continues

posteriad to become the posterior origin, the second becomes

the left M. sternotrachealis, and the third passes across

the ventral surface of the trachea to emerge with the right

M. sternotrachealis. The third branch is lacking on the

right side in Rallus and is absent on both sides in Fulica,

although in the latter genus the muscles on the two sides

are in contact by a thin ventral sheet (in Aramus there is no

contact between the muscles of the two sides, little or no

contribution to M. sternotrachealis, and on each side the mus-

cle divides into two heads, both of which continue to the

posterior origin). In both rallids the anterior origin is

from a smaller and more posterior portion of the ventral

surface of the cricoid than in Aramus. The posterior origin

is fleshy in both rallids (as in Aramus), but in Fulica it

is much wider. The insertion on the trachea is generally

weaker in Rallus than in Fulica (or Aramus).

Summary. This muscle is somewhat variable among the

three families and has intrafamilial differences in the

Gruidae and Rallidae. Aramus agrees with the rallids in

having a fleshy posterior origin, compared with the tendinous

one in the gruids. In the rallids the muscle gives off large

branches to form M. sternotrachealis, but in the non-rallids






84

there is little or no contribution to that muscle. Balearica

is similar to Fulica in the high degree of development of the

muscle, but it is considerably greater in the latter genus.

Unique specializations include the divided posterior end in

Aramus, the complete separation into two distinct muscles in

Grus, and the remarkable asymmetry in Rallus.


36. M. sternotrachealis

Small rounded muscle, about 1.5 mm in diameter and

about 30 mm long. Located in lateral region of space ante-

rior to heart. Connects trachea to rib cage, and also at-

taches to M. obliquus abdominis externus, to M. scalenus and

to Mm. intercostales externi.

Proximal end deep to anterior edge of M. obliquus ab-

dominis externus. Distal end contacts M. tracheolaryngeus.

Proximal end lies superficial to a small posterodorsal por-

tion of deep part of M. sternocoracoideus.

Origin. Arises by wide aponeurosis from ventral centi-

meter of last cervical rib and from upper third of first

sternal rib. Attaches also to portions of 1. scalenus, M.

obliquus abdominis externus, and most anterior of Mm. inter-

costales externi. Aponeurosis narrows abruptly, becomes

fleshy, and soon changes into rounded belly.

Insertion. Attaches to side of posterior end of tra-

chea, between the two slips of M. tracheolaryngeus, just

posterior to their point of origin.

Action. Retracts trachea, lengthening it and decreas-

ing tension on syrinx (see Miskimen, 1951).





85

Comparisons. In the Gruidae the muscle in Balearica

originates, less extensively than in Aramus, from the angle

between the sternal and vertebral parts of the first true

rib, but in Grus the origin is from the sternocoracoidal

process of the sternum. These two locations of the origin

in the gruids were described by Beddard (1898). In both

cranes the muscle inserts directly on M. tracheolaryngeus

(inserts between the two slips of that muscle in Aramus).

In the Rallidae the origin resembles that of Aramus,

but is somewhat more extensive on the left side. In both

rallids the muscle inserts as a branch of M. tracheolaryngeus

(see the description of that muscle). In Rallus the right

muscle divides and contributes to M. tracheolaryngeus on

both sides, but the left muscle is unbranched in Rallus, and

both sides are unbranched in Fulica (in Aramus both sides are

unbranched and have little connection to M. tracheolaryngeus).

In both rallids the insertion of the muscle on the right

side is slightly posterior to the left insertion (in Aramus

the insertions are symmetrical).

Summary. In Aramus the muscle has very little connection

to M. tracheolaryngeus, but there is more in the Gruidae, and

in the Rallidae the two muscles are continuous with each

other. Grus is distinct from Balearica and the non-gruids in

having the origin from the sternum. The rallids are unique

in having both the origin and the insertion asymmetrical.







37. M. thyroarytenoideus

Small and flattened triangular muscle. Located on pos-

terolateral portion of larynx. Attaches to cricoid and to

arytenoid cartilages.

Anterolateral edge adjacent to portion of origin of M.

thyrohyoideus arising from larynx. Posterolateral corner of

belly ventral to insertion of portion of small slip of M.

tracheohyoideus. Superficial, in dorsal view of larynx, to

M. constrictor glottidis.

Origin. Arises fleshily from posterior edge of cricoid

and dorsal side of posterolateral portion of lateral cricoid.

Insertion. Inserts fleshily on lateral edge of aryten-

oid cartilage.

Action. Opens glottis by moving arytenoid laterad.

Summary. The pattern of this muscle is the same in all

the genera studied in the three families.


38. M. constrictor qlottidis

Small and flattened, triangular muscle. Located on

dorsal side of larynx. Attaches to medial and lateral cri-

coids and to arytenoid.

Deep in dorsal view to M. thyroarytenoideus. Antero-

lateral edge adjacent to portion of origin of M. thyrohy-

oideus arising from larynx.

Origin. Originates fleshily from medial cricoid and

from dorsal surface of lateral flange on posterior half of

arytenoid.






87

Insertion. On medial side of anterior half of lateral

cricoid.

Action. Closes glottis.

Comparisons. In the Gruidae the portion of the origin

from the lateral flange of the arytenoid is lacking in Grus

(as in Aramus), and the insertion is on connective tissue

around the anterior end of the arytenoid as well as on the

lateral cricoid (only on the lateral cricoid in Aramus).

This muscle was not found in Balearica, but the region

was not well preserved. The muscle is presumably present in

a reduced condition in this crane.

In the Rallidae the muscle in Rallus arises only from

the medial cricoid (arises also from the lateral flange of

the arytenoid in Aramus), but in Fulica it arises from the

medial cricoid and all along the side of the arytenoid car-

tilage. In Rallus the insertion is partly on connective tis-

sue around the anterior end of the arytenoid and partly on

the middle of the dorsomedial rim of the lateral cricoid

cartilage (in Aramus the insertion is only on the anterior

half of the lateral cricoid). In Fulica the insertion is

only on the lateral cricoid, but it occupies the entire dor-

somedial edge.

Summary. Some rearrangement of the muscle has apparently

occurred in the evolution of the various genera. In Aramus,

and even more so in Fulica, the origin is moved anteriorly

onto the arytenoid. This attachment may be associated with a

need for more effective closing of the glottis in these two





88

underwater feeders. The muscle is essentially the same in

Grus and Rallus. Its presence is uncertain in Balearica.


Muscles of the Orbit


39. M. orbicularis palpebrarum

This muscle sheet is greatly reduced in the limpkin, and

is represented by only a few fibers on the inner side of the

lower lid. Its action (Shufeldt, 1890) is to close the eye,

mainly by raising the lower lid.

Comparisons. In the Gruidae it is apparently better

developed in Grus, arising from the anterior end of the jugal

bar and from the lacrimal bone and inserting mainly on the

lower eyelid. Only a few fibers of the muscle could be found

in Balearica, perhaps partly because of inadequate preserva-

tion in the region.

In the Rallidae no trace of the muscle was found.

Summary. The muscle exists as a recognizable sheet only

in Grus. It is much reduced in the other genera and is

probably absent in Rallidae.


40. M. elevator palpebrae
superioris

Very thin, wide sheet with few contractile fibers.

Covers upper side of eyeball. Attaches to roof of orbit and

to upper lid.

Encloses dorsal side of eyeball and eye muscles on that

surface.

Origin. Arises from inner edge of roof of orbit.






89

Insertion. Inserts into inner side of upper lid.

Action. Helps open eye by raising upper lid.

Summary. The muscle is the same in the limpkin, the

two cranes, and both rallids.


41. M. depressor palpebrae
inferioris

Very thin, wide sheet with few contractile fibers.

Covers posteroventral region of eyeball. Attaches to inter-

orbital septum and to lower lid.

Superficial to M. rectus externus and M. rectus inferior.

Origin. Arises from ventral region of interorbital

septum, along narrow line just ventral to origins of M. rec-

tus inferior and M. rectus externus.

Insertion. Fuses to inner side of most of length of

lower lid.

Action. Opens sye by depressing lower lid.

Comparisons. In the Gruidae it arises from a very small

area just dorsal to the anterior end of the origin of the M.

protractor quadratus (the area of origin is very elongate in

Aramus and located just ventral to the origins of the lower

two rectus muscles).

In the Rallidae the muscle in Rallus is essentially like

that of Aramus, but in Fulica the line of origin is longer

and extends farther anteriorly.

Summary. The origin of the muscle in the two cranes is

small and located posteroventral to the elongate origin of

Aramus and the two rallids. Otherwise the muscle is similar

in all three families.







42. M. quadratus nictitantis

Thin, somewhat rhomboidal sheet with bundles converging

to smaller ventral edge. Visibly separate in upper region

into smaller anterior and larger posterior portions. Lies

over most of dorsal region of inner side of eyeball. At-

taches to sclera and to tendon of M. pyramidalis nictitantis.

In medial view of eye, lies partly deep to M. obliquus

superior, to M. rectus superior, and to M. rectus externus.

Fascia of ventral edge encloses small tendon of M. pyramidalis

nictitantis.

Origin. Arises from thin longitudinal line extending

about one-third of circumference of eyeball, along its dorso-

medial aspect.

Insertion. Inserts as fascial pulley enclosing tendon

of M. pyramidalis nictitantis.

Action. Maintains tension on enclosed tendon, to hold

it away from optic nerve and to allow it to move nictitating

membrane.

Comparisons. In the Gruidae the muscle in Balearica

(as in Aramus) is large, with a partial division in the up-

per region, but in Grus the belly is considerably smaller

and apparently has no division.

In the Rallidae Rallus has a smaller belly with less of

it covered by M. rectus superior than in Fulica (or Aramus),

and the pulley is likewise smaller. In Rallus the pulley

enclosing the tendon of M. pyramidalis nictitantis is shorter

than in Fulica (or Aramus).






91

Summary. This muscle is generally similar in all the

genera examined, but some minor variations seem to have arisen

as adaptations. The belly is larger in Aramus, Balearica,

and Fulica than in Grus and Rallus, implying more use of the

nictitating membrane in the first three than in the latter

two. This may be related to the more aquatic habitat, at

least of Aramus and Fulica. A definite partial division in

the belly is present in each genus except Grus, but the sep-

aration is quite small in Rallus. The significance of this

is not clear, but it seems to correlate well with the differ-

ences in size.


43. M. pyramidalis nictitantis

Composed of small, flat, and elongately triangular belly

with very slender, rounded tendon leading from apex. Lo-

cated on anteroventral region of inner side of eyeball, just

anterodorsal to optic nerve. Tendon extends around to pos-

teroventral region of lateral surface of eyeball. Attaches

to sclera, to M. quadratus nictitantis, and to nictitating

membrane.

In medial view partly deep to M. obliquus inferior, to

M. rectus inferior, and to M. rectus internus. Inserting

tendon passes through pulley formed by free end of M.

quadratus nictitantis.

Origin. Arises from narrow longitudinal line of sclera

at anteroventral edge of inner side of eyeball.

Insertion. Small tendon leaves apex of belly, passes

through pulley of M. quadratus nictitantis, and passes to





92

ventrolateral region of eyeball to insert on posteroventral

corner of nictitating membrane.

Action. Pulls nictitating membrane posteriad, covering

cornea.

Comparisons. In the Gruidae the muscle is similar to

that of Aramus but it seems to be slightly smaller in Grus

than in Balearica (and Aramus).

In the Rallidae the muscle in Rallus is larger than in

Fulica (and considerably larger than in Aramus), and a smaller

portion is enclosed by the pulley of M. quadratus nictitantis

than in Fulica (or Aramus).

Summary. The muscle varies only in size among the genera

studied, but the differences occur within the Gruidae as well

as within the Rallidae. The larger size of this muscle in

Rallus is contrasted with the smaller size of M. quadratus

nictitantis in that genus. It would seem, on the basis of

the present muscle, that Rallus has more use of the nictitat-

ing membrane, but the smaller size of the former muscle indi-

cates that such an interpretation is oversimplified.


44. M. obliquus superior

Flat and fan-shaped. Lies on anterodorsal surface of

inner side of eyeball. Attaches to interorbital septum and

to sclera of eyeball.

Deep to M. elevator palpebrae superioris, and postero-

lateral edge deep to M. rectus superior. Superficial to

anterodorsal edge of M. quadratus nictitantis.






93

Origin. Arises fleshily from elongately oval scar at

extreme anterodorsal extent of interorbital septum.

Insertion. Inserts by short but wide aponeurosis, onto

sclera of posterodorsal region of inner side of eyeball,

mostly between origin of M. quadratus nictitantis and inser-

tion of M. rectus superior.

Action. Rolls eyeball inward in anterodorsal direction.

Comparisons. In the Gruidae the proximal end and its

area of origin are large (relatively small in Aramus). In

Balearica (and Aramus) the insertion is wider than in Grus.

In the Rallidae the elongate area of origin in Rallus

is oriented nearly vertically but is more nearly horizontal

in Fulica (and Aramus). In Rallus the belly is fleshy to

the point of insertion, but there is a short aponeurosis in

Fulica (and a more extensive one in Aramus).

Summary. Only very slight differences exist in this

muscle among the genera, but some occur within the Gruidae

and Rallidae. The two cranes differ from Aramus and the two

rallids in having a considerably larger area of origin for

this muscle.


45. M. obliquus inferior

Narrow and partially rounded band of muscle. Located

on anteroventral portion of inner side of eyeball. Attaches

to interorbital septum and to sclera.

Superficial to anterior edge of M. pyramidalis nicti-

tantis and to anterior edge of M. rectus internus.






94

Origin. Arises fleshily from rounded scar in middle of

extreme anterior edge of interorbital septum.

Insertion. Attaches by short aponeurosis to sclera in

anteroventral region of inner side of eyeball.

Action. Rotates eyeball in anteroventral direction.

Comparisons. In the Gruidae the muscle is widely flat-

tened (narrow and rounded in Aramus). In Balearica (and

Aramus) it originates from the middle of the anterior edge of

the interorbital septum. Fisher and Goodman (1955) show this

origin (p. 11) as arising with the rectus muscles from a

scar just anteroventral to the optic foramen. Apparently the

drawing is incorrect in this point, since they state (p. 37)

that the eye muscles follow the usual vertebrate pattern;

furthermore, skeletons examined of Grus grus, G. canadensis,

Anthropoides paradisea, and A. virgo all plainly show a scar

in the location described above for Balearica and Aramus.

In the Rallidae the area of origin in Rallus (nd Aramus)

is rounded, but it is elongate in Fulica and closer to the

origin of the other oblique muscles.

Summary. This muscle is similar in all genera dis-

sected, except perhaps Grus (see above).


46. M. rectus superior

Flat and elongately triangular muscle. Lies over pos-

terodorsal aspect of inner side of eyeball. Attaches to

interorbital septum and to sclera.

Deep to M. elevator palpebrae superioris. Superficial

to posterolateral corner of M. obliquus superior and to pot-

tion of M. quadratus nictitantis.





95

Origin. Originates fleshily from oval scar on postero-

dorsal edge of interorbital septum.

Insertion. Belly changes to thin aponeurosis in upper

third and inserts on narrow line on sclera in dorsal region

of inner side of eyeball, along dorsal edge of insertion of

M. obliquus superior.

Action. Rotates eyeball anterodorsad.

Comparisons. In the Gruidae the muscle is essentially

the same as in the limpkin.

In the Rallidae the muscle in Rallus differs from that

of Aramus only in arising from an area slightly closer to the

optic foramen. The origin in Fulica is located intermediate

to that of Rallus and Aramus.

Summary. The muscle is quite similar in all genera

studied.


47. M. rectus inferior

Small band of muscle. Located on posteroventral region

of inner side of eyeball. Attaches to interorbital septum

and to sclera.

Superficial to ventral edge of M. pyramidalis nictitantis.

Origin. Arises fleshily from oval scar on interorbital

septum, just anteroventral to optic nerve.

Insertion. Becomes aponeurotic in ventral 3 mm and in-

serts on anteroventral region of inner side of eyeball.

Action. Rotates eyeball anteroventrad.

Comparisons. In the Gruidae the area of origin is pos-

teroventral to the optic foramen (anteroventral to that fora-

men in Aramus).






96

In the Rallidae the muscle differs from that of the

limpkin only in being slightly more rounded.

Summary. The two cranes differ slightly from Aramus and

the rallids in the location of the origin, but the rails dif-

fer from Aramus and the cranes in having the belly slightly

more rounded. Other features are closely similar in all three

families.


48. M. rectus externus

Short, moderately thick band of muscle. Lies on postero-

ventral region of inner side of eyeball. Attaches to wall of

orbit and to sclera.

Superficial to portion of tendon of M. pyramidalis

nictitantis.

Origin. Arises fleshily from rounded scar, which par-

tially surrounds foramen for sixth cranial nerve, on wall of

orbit just posteroventral to optic foramen.

Insertion. Attaches by thin, short aponeurosis to sclera

of posterior region of inner side of eyeball.

Action. Rotates eyeball posteriad.

Comparisons. In the Gruidae the area of origin in

Balearica is posterior to the optic foramen, but in Grus it

is posterodorsal to the foramen (posteroventral to it in

Aramus). The muscle is otherwise similar in the two cranes

and the limpkin.

In the Rallidae the area of origin is wide and adjacent

to the posterior edge of the optic foramen (narrower in

Aramus and posteroventral to the optic foramen).




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