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Four New Pocket Gophers
of the Genus Cratogeomys from Jalisco, Mexico
BY
ROBERT J. RUSSELL
University of Kansas Publications
Museum of Natural History
Volume 5, No. 31, pp. 535-542
October 15, 1953
University of Kansas
LAWRENCE
1953
UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY
Editors: E. Raymond Hall, Chairman, A. Byron Leonard,
and Robert W. Wilson
Volume 5, No. 31, pp. 535-542
October 15, 1953
UNIVERSITY OF KANSAS
Lawrence, Kansas
PRINTED BY
FERD VOILAND, JR., STATE PRINTER
TOPEKA, KANSAS
1953
24-8662
Four New Pocket Gophers
of the Genus Cratogeomys from Jalisco, Mexico
By
ROBERT J. RUSSELL
In the course of my taxonomic study of the genus _Cratogeomys_, a high
degree of variation was found between several populations of these
gophers in central Jalisco. Two species, _C. gymnurus_ and _C.
zinseri_, occur in this part of the state. Previously _C. gymnurus_ was
known only from southern Jalisco and _C. zinseri_ only from extreme
eastern Jalisco, but through the efforts of J. R. Alcorn specimens were
obtained of both species in the central part of the state. These large
gophers are difficult to collect, and I am grateful to him for securing
this significant material. Costs of the field work were defrayed by the
National Science Foundation and the Kansas University Endowment
Association. Thanks are due also to those in charge of the United
States Biological Surveys Collection for the loan of comparative
material. Study of the recently acquired specimens taken in central
Jalisco reveals two undescribed subspecies each of _C. gymnurus_ and
_C. zinseri_. These may be known and described as
=Cratogeomys gymnurus tellus= new subspecies
_Type._--Female, adult, skull and skin, No. 33454 Mus. Nat.
Hist., Univ. Kansas; from 3 mi. W Tala, 4300 ft., Jalisco,
Mexico; obtained on June 2, 1949, by J. R. Alcorn, original
No. 9376.
_Range._--North-central Jalisco; known from several
localities in the vicinity of Tala.
_Diagnosis._--Size large (see measurements); tail long,
naked; hind foot small; color pale for species, upper parts
Kaiser Brown (capitalized terms are of Ridgway, Color
Standards and Color Nomenclature, Washington, D. C., 1912),
bases of individual hairs Plumbeous, tips Hazel, underparts
creamy-white, bases of hairs Plumbeous; skull large,
relatively narrow, rugose; zygomatic breadth narrower
posteriorly than anteriorly; rostrum shallow, relatively
broad in males, narrower in females; interorbital region
broad; braincase narrow and flattened; basioccipital
relatively wide, especially anteriorly; mastoid processes of
squamosal large, knoblike; paroccipital processes long,
extending laterally over more than half the width of mastoid
bullae; upper incisors projecting anteriorly; maxillary
teeth relatively large.
_Comparisons._--From topotypes of _C. g. gymnurus_ from
Zapotlan, Jalisco, the most closely related subspecies, _C.
g. tellus_ differs in: Body smaller (total length averaging
338 instead of 341 in females and 356 instead of 369 in
males); hind foot smaller (averaging 45 instead of 50 in
females and 47 instead of 51 in males); color more brownish
above, creamy-white rather than buffy below; skull smaller,
especially in females (basilar length averaging 55.3 instead
of 57.5 in females and 57.7 instead of 60.5 in males),
narrower, and more rugose; zygomatic breadth less in females
(averaging 42.5 compared with 46.2), greater in males (48.0
compared with 46.7); zygomata more nearly parallel; auditory
bullae relatively smaller; mastoid processes of squamosal
larger, knoblike; paroccipital processes longer, extending
farther laterally; rostrum less massive; upper incisors
projecting anteriorly, instead of being strongly recurved;
maxillary teeth relatively larger.
From near-topotypes of _C. g. inclarus_ from the Sierra
Nevada de Colima, Jalisco, _C. g. tellus_ differs in: Hind
foot smaller; color paler brownish above in contrast to
glossy black, creamy-white below rather than buffy, feet
clothed with whitish instead of brownish hairs; skull larger
(basilar length averaging 55.3 in females compared with
53.2, no males available for comparisons); zygomatic breadth
less; nasals longer, extending posterior to front edge of
anterior roots of zygomata rather than ending even with, or
slightly behind, them; rostrum more massive; mastoid
processes of squamosal larger; paroccipital processes
extending farther laterally; upper incisors projecting
anteriorly, rather than recurved; maxillary teeth larger
(length of maxillary tooth-row averaging 14.6 compared with
13.3).
Close comparison with _C. g. imparilis_ from Patzcuaro,
Michoacan, is not needed, _but C. g. tellus_ differs
especially in: Color of underparts and hairs of feet whitish
rather than brownish; skull smaller; zygomatic breadth
greater; interorbital constriction broader; nasals longer;
maxillary tooth-row longer.
_Measurements._--Averages of three adult females, including
type, and the measurements of an adult male (in parentheses)
from the type locality are: Total length, 338 (356); length
of tail, 92 (87); length of hind foot, 45 (47);
occipitonasal length of skull, 64.1 (68.7); basilar length,
55.3 (61.4); zygomatic breadth, 42.7 (48.0); interorbital
breadth, 9.6 (11.4); greatest height of cranium, taken from
palate perpendicular to line touching two highest points on
top of skull, 23.9 (25.3); least depth of rostrum, 10.6
(11.7); breadth of rostrum, 14.7 (16.5); length of nasals,
23.6 (25.2); width across mastoid processes of squamosal,
43.8 (49.7); height of occiput, 18.1 (19.9); length of
maxillary tooth-row, 14.6 (15.2).
_Remarks._--The distribution of _C. gymnurus_ is spotty; its
occurrence seemingly depends on edaphic conditions. The
isolation of soils with textures suitable to this animal has
resulted in the isolation of gopher populations. The
distribution is similar to that of species occurring on
islands. In this instance, however, the populations of
gophers are separated by soils of heavy texture which render
burrowing difficult or impossible for gophers. Such
conditions have led to a high degree of subspeciation in a
relatively short distance. For example, four subspecies of
_C. gymnurus_ occur in Jalisco, and, all are within an area
scarcely fifty miles in diameter.
_Cratogeomys gymnurus tellus_ is the northernmost subspecies
of _C. gymnurus_. It is known from only the vicinity of
Tala, west of Guadalajara, and its range probably is not
much more extensive than this because of the localized
distribution of suitable soils.
_Specimens examined._--Total number ten, as follows: 3 mi. W
Tala, type locality, 5; 1 mi. NE Tala, 3; 1 mi. S El
Refugio, 2.
=Cratogeomys gymnurus atratus= new subspecies
_Type._--Female, adult, skull and skin, No. 31880 Mus. Nat.
Hist., Univ. Kansas; from Top of Cerro Viejo de Cuyutlan,
9700 ft., 19 mi. S and 9 mi. W Guadalajara, Jalisco, Mexico;
obtained on February 17, 1949, by J. R. Alcorn, original No.
7902.
_Range._--Known only from the type locality on the Cerro
Viejo.
_Diagnosis._--Size small (see measurements); tail long; hind
foot small; color dark, upper parts glossy Blackish Brown,
bases of hairs Plumbeous, sides Chestnut Brown, underparts
Pale Ochraceous-Buff or Warm Buff mixed with Plumbeous of
the hair bases; skull small, lightly constructed, relatively
deep; zygomata relatively weak; zygomatic breadth wider
posteriorly than anteriorly; rostrum relatively wide,
especially in males; nasals relatively long, truncate
posteriorly; interorbital constriction narrow; braincase
inflated; mastoid processes of squamosal only slightly wider
than zygomatic breadth; auditory bullae relatively large;
paroccipital processes weakly constructed, but extend
laterally over half the width of mastoid bullae; upper
incisors projecting anteriorly, rather than being strongly
recurved; maxillary teeth small.
_Comparisons._--From topotypes of _C. g. gymnurus_ from
Zapotlan, Jalisco, _C. g. atratus_ differs in: Body smaller
(total length averaging 300 in females compared with 341, a
male measured 315 compared with an average of 363); tail
shorter, hind foot smaller; color of upper parts darker,
glossy Blackish-Brown rather than reddish brown, underparts
paler; skull smaller (basilar length averaging 48.6 compared
with 57.5, a male measured 50.0 compared with an average of
59.0); zygomata more weakly constructed; zygomatic breadth
less, and wider posteriorly than anteriorly; braincase more
inflated; nasals shorter; rostrum relatively narrower and
shallower; width across mastoid processes of squamosals
less; paroccipital processes less strongly constructed,
extending farther laterally; upper incisors projecting
anteriorly rather than being strongly recurved; maxillary
teeth smaller (length of maxillary tooth-row averaging 11.2
compared with 14.9).
From _C. g. tellus_, that occurs to the northwest, _C. g.
atratus_ differs in: Body smaller; hind foot slightly
smaller; upper parts darker; underparts Pale Ochraceous-Buff
rather than creamy-white; skull smaller (see measurements);
zygomatic breadth less, and wider posteriorly than
anteriorly; nasals shorter, truncate posteriorly rather than
emarginate; rostrum narrower and shallower; maxillary teeth
smaller.
From near-topotypes of _C. g. inclarus_ from the Sierra
Nevada de Colima, _C. g. atratus_ differs in: Body slightly
smaller; hind foot smaller (averaging 42 compared with 49);
color of upper parts near the same, underparts paler; skull
smaller, narrower, weaker in construction; zygomatic breadth
less; nasals relatively longer, but actually shorter
(averaging 19.7 compared with 20.3); upper incisors
projecting anteriorly rather than being recurved; maxillary
teeth smaller.
_Measurements._--The type and an adult female (its
measurements in parentheses) yield measurements as follows:
Total length, 300 (299); length of tail, 78 (83); length of
hind foot, 43 (40); occipitonasal length of skull, 56.3
(55.5); basilar length, 49.3 (47.8); zygomatic breadth, 37.9
(36.5); interorbital breadth, 8.7 (8.1); greatest height of
cranium, as explained above, 21.6 (20.7); least depth of
rostrum, 9.2 (8.8); breadth of rostrum, 12.8 (12.7); length
of nasals, 19.4 (20.0); width across mastoid processes of
squamosal, 38.2 (37.1); height of occiput, 16.9 (17.3);
length of maxillary tooth-row, 11.9 (11.3).
_Remarks._--_Cratogeomys gymnurus atratus_ is the smallest
subspecies known for the species, and is so distinct from
other described subspecies, that it is difficult to select
one as the closest relative. In color, _C. g. atratus_
closely resembles _C. g. inclarus_, which occurs at
comparable elevations in the Sierra Nevada, but the skulls
are unlike. Among named subspecies of _C. gymnurus_, the
skull of _tellus_ most closely resembles that of _atratus_,
and, although they differ greatly in size, _C. g. tellus_
seems to be the closest relative of _C. g. atratus_.
This newly described subspecies is known only from Cerro
Viejo and is probably restricted to the higher elevations on
this mountain.
_Specimens examined._--Seven, Top of Cerro Viejo de Cuyutlan,
19 mi. S and 9 mi. W Guadalajara.
=Cratogeomys zinseri zodius= new subspecies
_Type._--Male, adult, skull and skin, No. 31879 Mus. Nat.
Hist., Univ. Kansas; from 13 mi. S and 15 mi. W Guadalajara,
Jalisco, Mexico; obtained on February 6, 1949, by J. R.
Alcorn, original No. 7747.
_Range._--Known only from the type locality.
_Diagnosis._--Size small (see measurements); tail short; hind
foot small; upper parts Sayal Brown, underparts Pinkish Buff,
hind foot whitish; skull small, narrow; outline of dorsal
profile of skull concave; zygomatic breadth narrow; nasals
actually short, but relatively long; width across mastoid
processes of squamosal short; auditory bullae inflated;
interorbital constriction narrow; maxillary teeth relatively
large.
_Comparisons._--From topotypes of _C. z. zinseri_ from Lagos,
Jalisco, _C. z. zodius_ differs in: Body smaller (see
measurements); tail shorter, hind foot smaller; upper parts
dull brownish instead of reddish-brown, underparts paler,
hairs of feet whitish instead of brownish; skull smaller,
especially in females, narrower; dorsal profile of skull
concave or flat (females) rather than convex; zygomatic
breadth less; rostrum narrower and shallower; nasals actually
shorter, but relatively longer in relation to length of
skull; width across mastoid processes of squamosal shorter;
maxillary teeth smaller.
_Measurements._--The type and an adult male (his measurements
in parentheses) yield measurements as follows: Total length,
318 (324); length of tail, 95 (89); length of hind foot, 41
(41); occipitonasal length of skull, 60.5 (59.1); basilar
length, 52.4 (51.8); zygomatic breadth, 40.6 (39.0);
interorbital breadth, 8.3 (8.8); greatest height of cranium,
as explained above, 22.6 (22.4); least depth of rostrum, 11.2
(10.4); breadth of rostrum, 13.3 (13.9); length of nasals,
21.7 (21.2); width across mastoid processes of squamosal,
37.1 (36.8); height of occiput, 17.7 (17.9); length of
maxillary tooth-row, 13.0 (13.3). A nearly adult female
measured: Total length, 292; length of tail, 81; length of
hind foot, 39; occipitonasal length of skull, 53.3; basilar
length, 46.5; zygomatic breadth, 34.1; interorbital breadth,
7.8; greatest height of cranium, 21.0; least depth of
rostrum, 9.8; length of nasals, 18.0; width across mastoid
processes of squamosal, 32.2; depth of occiput, 15.9; length
of maxillary tooth-row, 12.1.
_Remarks._--This newly described subspecies is the smallest
of known races of _C. zinseri_, and it is seemingly more
closely related to _C. z. zinseri_ than to the subspecies
newly named below from the north end of Lago Sayula. The
skulls of females are especially small and delicate in
structure; the males are larger with more massive skulls.
_C. z. zodius_ is known to occur in the foot hills north of
the Cerro Viejo, the mountain from which _C. g. atratus_ was
described above.
_Specimens examined._--Seven, 13 mi. S and 15 mi. W
Guadalajara.
=Cratogeomys zinseri morulus= new subspecies
_Type._--Male, adult, skull and skin, No. 36679 Mus. Nat.
Hist., Univ. Kansas; from N end Lago Sayula, 4400 ft., 9 mi.
N and 2 mi. E Atoyac, Jalisco, Mexico; obtained on March 23,
1950, by J. R. Alcorn, original No. 10889.
_Range._--Known only from the type locality in central
Jalisco.
_Diagnosis._--Size large (see measurements); tail short;
hind foot large; upper parts Fuscous-Black, strongly mixed
with Walnut Brown, underparts Cinnamon-Buff, bases of all
hairs Plumbeous; skull large, broad, rugose; outline of
dorsal profile slightly concave, almost flat; zygomata
strongly constructed, maxillary arm almost touching
squamosal arm over jugal; wide across zygomata; nasals
actually and relatively long; rostrum relatively narrow;
auditory bullae inflated, relatively large; maxillary teeth
relatively large.
_Comparisons._--From topotypes of _C. z. zinseri_ from
Lagos, Jalisco, _C. z. morulus_ differs in: Tail shorter
(averaging 96 in females compared with 101, 94 in males
compared with 115); color darker above, Fuscous-Black
instead of Cinnamon-Rufous, underparts paler; skull larger
(occipitonasal length 63.7 rather than averaging 58.5 in
females and 68.6 rather than 63.1 in males); wide across
zygomata; nasals actually and relatively longer; rostrum
relatively narrower; wider across mastoid processes of
squamosal; auditory bullae inflated, relatively larger;
maxillary teeth larger.
From _C. z. zodius_, that occurs to the northeast, _C. z.
morulus_ differs in: Body larger (see measurements); hind
foot larger; color of upper parts darker, underparts paler;
skull much larger, broader, more rugose; dorsal profile of
skull slightly concave rather than convex; wider across
zygomata; nasals actually and relatively longer; rostrum
broader, more massive; wider across mastoid processes of
squamosal; auditory bullae larger; maxillary teeth larger.
_Measurements._--The type and an adult female (her
measurements in parentheses) from the type locality measure:
Total length, 358 (338); length of tail, 94 (97); length of
hind foot, 49 (45); occipitonasal length of skull, 68.6
(63.7); basilar length, 58.0 (55.6); zygomatic breadth, 49.3
(45.0); interorbital breadth, 9.6 (8.9); greatest height of
cranium, as explained above, 26.1 (24.6); least depth of
rostrum, 12.5 (10.8); breadth of rostrum, 14.5 (13.7);
length of nasals, 25.9 (22.5); width across mastoid
processes of squamosal, 47.7 (42.8); height of occiput, 19.8
(17.8); length of maxillary tooth-row, 13.9 (13.8).
_Remarks._--_Cratogeomys zinseri morulus_ is the darkest
subspecies known of _C. zinseri_. It differs widely from
other subspecies of this species in color and the large size
of the skull.
_Cratogeomys zinseri_ occurs over the same general area as
_C. gymnurus_ in central Jalisco, although these two species
seemingly do not share the same local habitat. _C. zinseri_
differs from _C. gymnurus_ as follows: Tail relatively
longer; skull wider across zygomatic arches than across
mastoid processes of squamosal (reverse true in _C.
gymnurus_); zygomata strongly bowed outward anteriorly;
maxillary arm of zygomata almost touching squamosal arm
(instead of widely separated from each other) above jugal;
rostrum relatively narrower, less massive; border of nasals
parallel or laterally swollen instead of gradually tapering.
_Specimens examined._--Four, N end of Lago Sayula, 9 mi. N
and 2 mi. E Atoyac.
_Museum of Natural History, University of Kansas, Lawrence. Transmitted
June 12, 1953._
24-8662
* * * * *
Transcriber's Notes:
Page 538: Changed lead to led (conditions have lead to a high degree).
Bold text is shown within =equal signs=.
Italicized text is shown within _underscores_.Project Gutenberg
Four New Pocket Gophers of the Genus Cratogeomys from Jalisco, Mexico
Russell, Robert J.
Chimera61
Academic