Table Of ContentPUBLISHED BY THE AMERICAN MUSEUM OF NATURAL HISTORY
CENTRAL PARK WEST AT 79TH STREET, NEW YORK, NY 10024
Number 3294, 53 pp., 21 figures, 4 tables April 25, 2000
Comparative Myology of Moles and the
Phylogeny of the Talpidae (Mammalia, Lipotyphla)
HOWARD P. WHIDDEN1
CONTENTS
Abstract ............................................................... 2
Introduction ............................................................ 2
Specimens Examined ................................................... 4
Descriptive Myology .................................................... 6
Branchiomeric Musculature ............................................ 6
Trigeminal Field ................................................... 6
Facial Field ....................................................... 9
Glossopharyngeal Field ............................................ 15
Vagus Field ...................................................... 15
Accessory Field ................................................... 16
Myotomic Musculature ............................................... 17
Axial Musculature ................................................. 17
Pectoral Limb Musculature ......................................... 21
Pelvic Limb Musculature ........................................... 33
Phylogenetic Analysis .................................................. 42
Methods ............................................................ 42
Characters .......................................................... 42
Results ............................................................... 45
Discussion ............................................................ 45
Systematics ......................................................... 45
Biogeographic History ............................................... 48
Acknowledgments ..................................................... 50
References ............................................................ 50
1Assistant Professor, Department of Biology, Augustana College, Rock Island, IL 61201; Research Associate,
DivisionofVertebrateZoology,AmericanMuseumofNaturalHistory.
Copyright(cid:113)AmericanMuseumofNaturalHistory2000 ISSN0003-0082/Price$6.70
2 AMERICAN MUSEUM NOVITATES NO. 3294
ABSTRACT
The skeletal musculature of 11 talpid genera is described,and58myologicalcharactersare
defined and used in a phylogenetic analysis of the Talpidae. This analysis included the out-
group taxa Atelerix (Erinaceidae) and Blarina (Soricidae), and it discovered a single most
parsimonioustree.InclusionofUropsilusinamonophyleticTalpidaeneedsfurtherevaluation,
but there is very strong support for the monophyly of other talpids. Contrary to previous
interpretationsoftalpidrelationships,thisphylogeneticanalysisindicates(1)thefullyfossorial
moles Parascalops, Scalopus, Scapanus, and Talpa are monophyletic; (2) the Eurasian genus
Talpa is sister taxon to the North American genera Scalopus and Scapanus; and (3) the long-
tailed mole Scaptonyx is part of a clade with the shrew moles Neurotrichus and Urotrichus.
Preliminary biogeographic analysis suggests that the Talpidae originated in the Old World,
and that there were separate dispersals from Eurasia to North America by Condylura, Neu-
rotrichus, Parascalops, and the common ancestor of Scalopus and Scapanus.
INTRODUCTION are probably best described as ambulatory.
The American and Japanese shrew moles
The mammalian family Talpidae contains
(Neurotrichus and Urotrichus, respectively)
the fossorial moles, the shrew moles,andthe
have reduced ear pinnae, thickened palms,
desmans. The Talpidae has traditionallybeen
and heavy claws. They will burrow at least
classifiedintheorderInsectivora(e.g.,Simp-
occasionally(Nowak,1991),andcanbecon-
son, 1945; Hutterer, 1993), although chang-
sidered semifossorial.Thehabitsofthelong-
ing views on mammalian phylogeny and
tailed mole (Scaptonyx) have apparently not
classification have led some recent workers
been recorded (Nowak, 1991), but this mole
toplaceiteitherintheorderLipotyphla(e.g.,
is similar in external form to Neurotrichus
Butler, 1972, 1988; MacPhee and Novacek,
and Urotrichus, and it is probably also semi-
1993) or the order Erinaceomorpha (e.g.,
McKenna and Bell,1997).Thereisdisagree- fossorial. The desmans (Desmana and Gal-
ment as to the sister group of talpids, with emys) are semiaquatic, with webbed feet and
some workers holding that it is the Erinacei- a tail that is laterally compressed for at least
dae(McDowell,1958;VanValen,1967;Mc- part of its length (Nowak, 1991). The star-
Kenna and Bell, 1997) and others that it is nosed mole (Condylura) is an accomplished
the Soricidae (Butler, 1988; Carroll, 1988). burrower, with broadened forefeet and heavy
Although it is generally agreed that talpids claws. However, it also swims regularly in
form a monophyletic lineage (Yates and fresh water, and Yates and Moore (1990)
Moore, 1990), there have been no explicit considered it to be aquatic/fossorial. The re-
statements of derived characters for the maininggenera(Parascalops,Scalopus,Sca-
group. Recent classifications of the Talpidae panulus, Scapanus, and Talpa) are the New
(Van Valen, 1967; Yates, 1984; Corbet and and Old World burrowing moles, and they
Hill, 1991; Hutterer, 1993; McKenna and can be considered fully fossorial.
Bell, 1997) have recognized between 12 and The oldest fossils assigned to the Talpidae
17 genera and between 31 and 42 species.In are from the late Eocene of Europe (McKen-
the present study I follow the classification naandBell,1997).Incontrast,talpidsdonot
of Corbet and Hill (1991), which recognized appear in North America until the late Oli-
12 genera and 31 species (table 1). gocene(McKennaandBell,1997).Thistime
Living talpids exhibit a remarkable diver- difference suggests a Eurasian origin for the
sity of lifestyles andlocomotorhabits,which group, with subsequent dispersal to North
Yates and Moore (1990) categorized as am- America. However, it is not clear when
bulatory, semifossorial,semiaquatic,aquatic/ moles arrived in North America, how many
fossorial,andfossorial(table1).TheChinese invasions there were, or what route(s) they
shrew moles (Uropsilus) have well-devel- took. Dobson (1891) believed that the New
oped ear pinnae and unspecialized forefeet World fossorial moles are derived from an
(Nowak, 1991), and their locomotor habits Old World ancestor similar to Talpa that
2000 WHIDDEN: MYOLOGY OF MOLES 3
crossed a Bering land bridge, and that the but they both separate the fully fossorialOld
AmericanshrewmoleNeurotrichusisthere- World genus Talpa from the fully fossorial
sult of a second invasion by a form similar New World genera Parascalops, Scalopus,
to the Japanese shrew mole Urotrichus. andScapanus(fig.1).Thisimplieseitherthat
Hutchison (1976) contended that only am- full fossoriality evolved independently in
bulatory moles could have crossed a Bering Talpa and the North American fossorial mo-
land bridge, implying the independentdevel- les, or that some taxa secondarily lost fos-
opment of full fossoriality in the New and sorialhabits.Also,bothphylogeniesseparate
Old World fossorial moles. Vaughan (1986) Scaptonyx from Neurotrichus and Urotri-
heldthattheTalpidaereachedNorthAmerica chus, which implies that the similarity in ex-
across a North Atlantic bridge in the early ternal form between Scaptonyx and the two
Tertiary,buthedidnotcommentonthenum- shrew moles is due either to primitive fea-
ber of dispersal events.Moore(1986)argued tures or to convergence.
for three separate invasions of North Amer- Comparative myology has been avaluable
ica: one for the New World burrowingmoles source of characters for systematic analyses
(Parascalops, Scalopus, and Scapanus), one of mammals (e.g., Klingener, 1964; Woods,
for Condylura,andanotherforNeurotrichus. 1972; Griffiths, 1982; Dunlap et al., 1985;
Recent phylogenetic hypotheses for the Stein,1986,1990;Ryan,1989).Althoughin-
Talpidae have been based on osteology tergenericvariationinmyologyhasbeennot-
(Hutchison, 1968, 1976), allozymes (Yates ed in talpids (Dobson, 1882–1890; Camp-
and Greenbaum, 1982; Moore, 1986), and a bell, 1939; Reed, 1951), myological charac-
combination of genic, cytogenetic, and mor- ters have never been used for the phyloge-
phological characters (Yates and Moore, netic analysis of the group. In the present
1990). However, these previous studies have study I use comparative myology as a new
not included data matrices, and only Moore source of characters for the phylogenetic
(1986) provided an explicit discussion of analysis of the Talpidae. I describe the skel-
characters and character polarities. In addi- etal musculature of 11 talpid genera, define
tion, only Hutchison (1976) and Yates and muscle differences between taxa as charac-
Moore(1990)includedallextantgenera.The ters, and use these characters in the first true
phylogenies of Hutchison (1976) and Yates cladistic analysis of talpid phylogeny. I then
and Moore (1990) differ in important ways, compare the clades discovered in this anal-
4 AMERICAN MUSEUM NOVITATES NO. 3294
Fig. 1. Two recent phylogenetic hypotheses for the Talpidae, modified to include only extant taxa
and to conform to the generic classification of Corbet and Hill (1991). A, Hutchison (1976:13), based
on osteology; B, Yates and Moore (1990:15), based on morphology, genetics, and cytogenetics.
ysis with those recognized in previous phy- Also, I did not dissect in detail the muscles
logenies, addressing three specific questions: associated with the ear pinna of Uropsilus
(1)Didfullfossorialityevolveindependently becausetheotherstudytaxadonothavepin-
in the New and Old World burrowing moles, na muscles. Several of the specimens avail-
or are the fully fossorial moles monophylet- able to me were not intact, and therefore I
ic? (2) Is the similarity between Scaptonyx, was not able to describe all muscles for all
Neurotrichus, and Urotrichus due to primi- taxa; notable gaps are in the cranial muscles
tive features or convergence, or are these of Galemys and in the upper pelvic limb
semifossorial taxa monophyletic? (3) How muscles of Scaptonyx. Furthermore, fluid-
many dispersal events were involved in the preserved specimens of Desmana, Galemys,
origin of the Recent North American mole Scaptonyx, Uropsilus, and Urotrichus are
fauna? rareinmuseumcollections,andintheseIdid
not dissect the deeper axial muscles. These
SPECIMENS EXAMINED muscles showed little variation in the other
taxa, and their dissection would have caused
I dissected 37 fluid-preserved talpid spec-
considerable damage to the specimens.
imens(table2),including11ofthe12genera
Dissections were made under a Bausch
recognized by Corbet and Hill (1991). The
and Lomb Stereozoom Microscope (3.5–
only genus that I was not able to dissect is
30(cid:51)) and a Nikon SMZ-U Stereoscopic Mi-
Scapanulus, which is very rare in study col-
croscope (3.75–37.5(cid:51)). Dermal muscles
lections (Nowak, 1991). I assumed that the
polytypic genera Scapanus, Talpa, and Uro- were dissected by first shaving the fur and
trichus are monophyletic, and since previous vibrissae from the head and neck region,and
myological studies of mammals have found then gradually shaving and peeling away the
little myological variation below the generic sequentiallayersoffacialmuscles.Aniodine
level (Rinker and Hooper, 1950; Rinker, stain (Bock and Shear, 1972) was used to
1963; Stein, 1986), I considered Scapanus identifythefiberdirectionofthesmallestand
townsendii, Talpa europaea, and Urotrichus thinnest muscle layers.
talpoides as representativeoftheirrespective Muscle descriptions include information
genera. I also assumed that Uropsilus is on origin, insertion, shape, and topographic
monophyletic, and I let U. gracilis and U. position relative to other anatomical struc-
soricipes represent this genus. tures. Nongenetic factors such as mode of
I dissected the entire skeletal muscular preservation and the size, age, and condition
systemwiththeexceptionoftheextrinsicoc- of the specimens at the time of preservation
ular muscles, the diaphragm, the perineum, may all contribute to apparent variation in
andmostoftheintrinsicmusclesoftheback. myology (Stein, 1986; personal obs.), and
2000 WHIDDEN: MYOLOGY OF MOLES 5
therefore I was conservative in identifying Dobson (1882–1890), Campbell (1939),
muscle differences between taxa. I did not Reed(1951),Gaughran(1954),andMeinertz
attempttomakeprecisesizecomparisons,al- (1978a) for muscle nomenclature; where
though I remark on obvious differences in these authorities disagree I note synonyms
muscle size between taxa. Muscle innerva- under Remarks. Problems of homology are
tions were determined only where homology also discussed underRemarks.IfollowReed
was in question. (1951) and Gaughran (1954) in naming os-
The muscle descriptions are arranged into teological structures that serve as points of
groups according to innervation and topo- origin and insertion for muscles. The orien-
graphic position. The myology of Parascal- tation of the talpid humerus varies consid-
ops is used as a standard for comparison in erablyinthedifferentgenera,andinthefully
the descriptions, and conditions in the other fossorial genera it is abducted to such a de-
generaarediscussedunderRemarks.Ifollow greethatitsdistalendisdorsaltotheglenoid
6 AMERICAN MUSEUM NOVITATES NO. 3294
Fig. 2. Masticatory muscles of Parascalops.
articulation. Therefore, its anatomically me- from the lateral wall of the skull and from
dial surface is actually lateral in position. the medial surface of the zygomatic arch.
However, to avoid confusion I use the terms INSERTION: The insertion of this muscle is
medial and lateral in the muscle descriptions complex. The anteriorfibersextendventrally
asifthehumeruswereorientedinthenormal to inserton thetip andanteriormarginofthe
quadrupedal position. coronoid process. The deep anterior fibers
Most muscles are illustrated with line fromthesideoftheskullinsertonthemedial
drawings of the condition in Parascalops, surface of the coronoid process. The dorsal
but the intrinsic muscles of the manus are fibers from the midline of the skull converge
illustratedforGalemysandtheintrinsicmus- to a stout insertion on the tip of thecoronoid
cles of the pes for Neurotrichus. The draw- process, with some fibers running onto the
ings were prepared with the aid of a camera medial surface. The posteriormost fibers ex-
lucida attachment for the Nikon SMZ-USte- tend anteriorly to insert along the posterior
reoscopicMicroscope,andtheyarenottothe margin of the coronoid process. The fibers
same scale. They are grouped after the mus- from the medial surface of the zygomatic
cle descriptions. arch extend anteriorly, then curve ventrally
to insert on the anterior margin of the coro-
DESCRIPTIVE MYOLOGY noid process.
REMARKS: This muscle has the same gen-
BRANCHIOMERIC MUSCULATURE eral form in Condylura, Desmana, Neurotri-
TRIGEMINAL FIELD chus, Parascalops, Scalopus, Scapanus,
Scaptonyx,Talpa,Uropsilus,andUrotrichus.
Masticatory Group
In Uropsilus, the portion from the medial
surface of the zygomatic arch is particularly
M. temporalis (fig. 2) well developed.
ORIGIN: From a broad area of the dorsal
and lateral skull, extending from the frontal M. masseter (figs. 2, 6, and 7)
almost to the occipital, and medially to the ORIGIN: A superficial layer from the max-
dorsal midline; some deeper fibers originate illary root and the lateral surface of the an-
2000 WHIDDEN: MYOLOGY OF MOLES 7
terior zygomatic arch, and a deep layer from Neurotrichus, Parascalops, Scalopus, Sca-
theventralsurfaceoftheposteriorzygomatic panus, Scaptonyx, Talpa, and Urotrichus.
arch. Some fibers of this muscle may insert on the
INSERTION: The superficial portion on the dorsal surface of the pterygoid hamulus;
lateral surface and posterior and ventralmar- these fibers are especially obvious in Con-
gins of the angular process, the deep portion dylura. The tendon of insertion of this mus-
in the masseteric fossa and along the ventral cle extends over the pterygoid hamulus, and
margin of the condylar process of the den- the belly of the muscle covers theeustachian
tary. tube.
REMARKS: This muscle has the same gen-
eral form in the 11 study taxa. The superfi- M. tensor tympani
cial masseter of Uropsilus originates from a I did not find this muscle in the taxa ex-
prominent tubercle at the maxillary root of amined.
the zygoma, as Hutchison (1968) suspected.
Fiedler (1953) considered the deep layer to
Mylohyoid Group
be a separate muscle, M. zygomaticomandi-
bularis. Zlabek (1938) provided a detailed M. digastricus, venter anterior (fig. 6)
descriptionofthismuscleforTalpaandGal- The posterior portion of the digastric is
emys (his Myogale), and Gaughran (1954) discussed with the muscles of the Facial
comparedanumberofpublisheddescriptions Field.
of the talpid masseter. ORIGIN: A lateral portion from a chevron-
shaped tendinous inscription with the poste-
M. pterygoideus externus rior belly of the digastric, and a medial por-
ORIGIN: As a dorsal head from the ventral tionfromatough,concavefascialsheet.This
marginofthefrontalboneandaventralhead fascial sheet extends posterolaterally from
from the orbitotemporal region. the midline to join the tendinous inscription
INSERTION: The fibers of the two heads between the anterior and posterior digastric
converge and attach on the medial surfaceof bellies.
the condylar process of the mandible. INSERTION: The lateral portion onto the
REMARKS: This muscle has the same gen- ventral surface of the mandible via a stout
eral form in Condylura, Desmana, Galemys, digastric tendon, the medial portion onto the
Neurotrichus, Parascalops, Scalopus, Sca- ventral surface of the mandible and the di-
panus, and Talpa. gastric tendon.
REMARKS: This muscle has the same gen-
Internal Pterygoid Group eral form in Condylura, Neurotrichus, Par-
ascalops, Scalopus, Scapanus, Scaptonyx,
M. pterygoideus internus Talpa, and Urotrichus. Uropsilushasnome-
ORIGIN: From an extensive areadorsaland dial portion to the anterior belly. Desmana
lateral to the pterygoid region. has a lateral portion similar to theothertaxa,
INSERTION: Over the entire medial surface but the medial portion becomes split, with a
of the angular process of the mandible. superficial layer originating from the tendon
REMARKS: This muscle has the same gen- of the opposite side, and a deep layer origi-
eral form in Condylura, Desmana, Galemys, nating from the median raphe of M. mylo-
Neurotrichus, Parascalops, Scalopus, Sca- hyoideusprofundus; bothlayersinsertonthe
panus, Scaptonyx, Talpa, and Urotrichus. digastric tendon near its attachment to the
mandible.Ididnotdiscerntheazygouscom-
M. tensor veli palatini ponent that Dobson (1882–1890) described
ORIGIN: From the ventral surface of the for Desmana. Gaughran (1954) did not iden-
skull, just anteromedial to the tympanicring. tify a tendinous inscription in this muscle in
INSERTION:Viaanaponeuroticsheetonthe Scalopus,andheidentifiedthelateralportion
posterior surface of the secondary palate. of the venter anterior as part of the venter
REMARKS: This muscle has the same gen- posterior. Fiedler’s (1953) interpretation of
eral form in Condylura, Desmana, Galemys, this muscle in Talpa is similar to mine.
8 AMERICAN MUSEUM NOVITATES NO. 3294
Fig. 3. Dorsal view of facial muscles of Parascalops; superficial muscles on left, deeper muscles
on right.
Fig. 4. Lateral view of facial muscles of Parascalops, M. sphincter colli superficialis removed.
2000 WHIDDEN: MYOLOGY OF MOLES 9
M. mylohyoideus, pars superficialis (fig. pinna, with a number of associated muscles
6) not found in other talpids; these muscles are
This muscle is a sheet of transverse fibers not described here.
that runs between the two halvesoftheman-
dible, attaching to theventralsurfaceofeach Superficial Facial Group
ramus; there is no indication of a median
raphe. This muscle lies deep to M. digastri- M. sphincter colli superficialis (fig. 3)
cus and superficial to M. geniohyoideus. ORIGIN: From the skin and connective tis-
REMARKS: This muscle has the same gen- sue of the ventral midline, where the anti-
eral form in the 11 study taxa. meres decussate.
INSERTION: On the side of the neck and on
the dorsal surface of the shoulder. Fibers of
M. mylohyoideus, pars profundus
M. sphincter colli superficialis appear to
ORIGIN: From the medial surface of the
merge with fibers of the pars intermediador-
mandible. The anterior fibers extend trans-
salis of M. sphincter colli profundus where
versely,whereasthemoreposteriorfibersex-
the two layers overlap.
tend posteromedially.
INSERTION: In a midventral raphe with fi- REMARKS: This muscle has the same gen-
eral form in Condylura, Desmana, Neurotri-
bers of the antimere, with the posteriormost
chus, Parascalops, Scalopus, Scapanus,
fibers attaching to the basihyal cartilage.
Scaptonyx,Talpa,Uropsilus,andUrotrichus.
REMARKS: This muscle has the same gen-
eral form in the 11 study taxa. The midven-
M. platysma and derivatives
tral raphe of this muscle is firmly attachedto
The platysmal layer consists of the prom-
M. geniohyoideus.
inent M. platysma myoides and the various
retroauricular muscles. M. cervico-auriculo-
FACIAL FIELD
frontalis (figs. 2 and 3) is a prominent retro-
The muscles supplied by the facial nerve auricularmusclethatoriginatesfromthedor-
are typically split into two groups, the su- sal surface of the neck, continuous with and
perficial facial muscles, or muscles of ex- medial to M. platysma myoides. M. mandi-
pression, and the hyoid constrictor muscles. bulo-auricularis, which extendsalongtheau-
The superficial facial muscles of therian ditory tube, also belongs in this group (Hub-
mammals consist of three distinct layers: M. er and Hughson, 1926). The remaining re-
sphinctercollisuperficialis,M.platysma,and troauricular muscles are deeperandoriginate
M. sphincter colli profundus (Huber, 1930, from the dorsal midline. They are thin, del-
1931). M. sphincter colli superficialis is the icate muscles that insert into the skin of the
most superficial of these and has transverse head, neck, and shoulder. In some mammal
fibers, M. platysma is the middle layer and groups an M. platysma cervicale encircles
haslongitudinalfibers,andM.sphinctercolli the neck, but I did not find this muscle in
profundus is the deepest layer and has trans- talpids.
verse fibers. According to Huber, M. sphinc-
ter colli superficialis forms at most a simple M. platysma myoides (figs. 3 and 4)
band encircling the neck, whereas Mm. pla- ORIGIN: In two parts: a large dorsal sheet,
tysma and sphincter colliprofundusgiverise which splits to form a pars frontalis and a
to a diversity of specialized facial muscles.I pars labialis superioris, and a smaller ventral
interpret the facial muscles of talpids in this sheet, the pars labialis inferioris. The dorsal
way, and follow Huber’s classification in my platysmal sheet originates with M. cervico-
treatment of these muscles. Meinertz (1978a auriculo-frontalis over a broad area of the
& 1978b) described in detail the facial mus- back and shoulder region, superficial to M.
cles of Erinaceus, Talpa, Suncus (his Pach- cutaneus maximus. Some fibers also arise
yura), and Sorex. Although I disagree with from the dorsal surface of the forelimb. Just
some of his interpretations, I have followed posterior to the ear opening, this sheet sep-
his names for these muscles except where arates from M. cervico-auriculo-frontalis to
noted. Uropsilus has a well-developed ear run ventral to the ear. Anterior to the ear, it
10 AMERICAN MUSEUM NOVITATES NO. 3294
splits to form the pars frontalis and the pars INSERTION:Intotheskinoverthetopofthe
labialis superioris.Theparslabialisinferioris head.
originates separately from the posterior and REMARKS: This muscle has the same gen-
ventral surfaces of the forelimb. eral form in Condylura, Desmana, Neurotri-
INSERTION: Pars frontalis on the bony ros- chus, Parascalops, Scalopus, Scapanus,
trum anterior to the eye and deep to M. cer- Scaptonyx,Talpa,Uropsilus,andUrotrichus.
vico-auriculo-frontalis, pars labialissuperior-
is into the corner of the mouth, and pars la- M. cervico-auricularis, pars superficialis
bialis inferioris into the intermandibular fas- (fig. 3)
cia, along the angle of the jaw, and in fascia ORIGIN: From the dorsal midline, contin-
on the side of the head. uous with the posterior margin of M. cervi-
REMARKS: The general form of this mus- co-occipitalis.
cle, with a pars frontalis, pars labialis super- INSERTION: On the posteromedial edge of
ioris, and pars labialis inferioris, is similarin the auditory canal.
Condylura, Desmana, Neurotrichus, Paras- REMARKS: This muscle has the same gen-
calops, Scalopus, Scapanus, Scaptonyx, Tal- eral form in the 11 study taxa.
pa, Uropsilus, and Urotrichus.
M. cervico-auricularis pars profundus
M. cervico-auriculo-frontalis (fig. 4) (fig. 3)
ORIGIN: From the skin over the shoulders ORIGIN: From the dorsal midline of the
and back, together with M. platysma myoi- neck, deep to M. cervico-auricularis parssu-
des pars dorsalis. perficialis.
INSERTION: On the rostrum just anterior to INSERTION: Into the skin over the forelimb.
the eye, superficial to M. platysma myoides REMARKS: This muscle has the same gen-
pars frontalis. eral form in Parascalops, Scalopus, Scapan-
REMARKS: This muscle has the same gen- us, and Talpa. In Condylura, Desmana, Gal-
eral form in Condylura, Desmana, Neurotri- emys, Neurotrichus, Scaptonyx, Uropsilus,
chus, Parascalops, Scalopus, Scapanus, and Urotrichus it inserts with the pars su-
Scaptonyx,Talpa,Uropsilus,andUrotrichus. perficialis on the posteromedial edge of the
This muscle separates from the platysmal auditory canal.
sheet to pass dorsal to the ear. It covers the
top of the head, where it is continuous at the M. occipitofrontalis
midline with its antimere. Some fibers from ORIGIN: From the occipital region of the
this sheetattach totheskinaroundthedorsal skull, adjacent to the dorsal midline and just
rim of the ear opening. Dobson (1882–1890) posterior and medial to M. temporalis.
grouped Mm. cervico-auriculo-frontalis and INSERTION: Via a long tendon into the in-
platysma myoides pars frontalis as M. fron- tegument over the snout.
tocuticularis. REMARKS: This muscle has the same gen-
eral form in Condylura, Desmana, Neurotri-
M. interscutularis chus, Parascalops, Scalopus, Scapanus,
The interscutularis is a thin band of fibers Scaptonyx,Talpa,Uropsilus,andUrotrichus.
extending across the dorsal midline and con-
necting the dorsal surfaces of the auditory M. mandibulo-auricularis
canals.Itliesdeeptotheotherfacialmuscles ORIGIN: From the dorsal margin of the an-
and superficial to M. temporalis. I found this gular process, just dorsal to M. pterygoideus
muscle in some specimens of Condyluraand internus.
Uropsilus, but it is very difficult to see, and INSERTION: Along the anteromedialsurface
I am not sure of its distribution in the other of the auditory tube.
study taxa. REMARKS: Similar in Condylura, Des-
mana, Galemys, Neurotrichus, Parascalops,
M. cervico-occipitalis (fig. 3) Scaptonyx, Uropsilus, and Urotrichus. Pre-
ORIGIN: From the dorsal midline just deep sent in Talpa, but it originates from the an-
to M. cervico-auriculo-frontalis. terior surface of the auditory bulla directly
