A New Doglike Carnivore, Genus Cynarctus, From the Clarendonian, Pliocene, of Texas

UNIVERSITY OF KANSAS PUBLICATIONS

MUSEUM OF NATURAL HISTORY

Volume 14, No. 10, pp. 135-138, 2 figs.

April 30, 1962


A New Doglike Carnivore, Genus Cynarctus,
From the Clarendonian, Pliocene, of Texas

BY

E. RAYMOND HALL and WALTER W. DALQUEST


UNIVERSITY OF KANSAS

LAWRENCE

1962




UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY

Editors: E. Raymond Hall, Chairman, Henry S. Fitch,
Theodore H. Eaton, Jr.


Volume 14, No. 10, pp. 135-138, 2 figs.
Published April 30, 1962

UNIVERSITY OF KANSAS
Lawrence, Kansas

PRINTED BY

JEAN M. NEIBARGER, STATE PRINTER

TOPEKA, KANSAS

1962

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A New Doglike Carnivore, Genus Cynarctus,
From the Clarendonian, Pliocene, of Texas

BY

E. RAYMOND HALL and WALTER W. DALQUEST


A study of a right maxilla bearing P3-M1 and part of a right mandibular
ramus bearing m2 (see figures) reveals the existence of an unnamed
species of cynarctine carnivore. It may be known as:

=Cynarctus fortidens= new species

    _Holotype._--Right maxilla bearing P3, P4, and M1, No. 11353
    KU; bluff on west side of Turkey Creek, approximately 75
    feet above stream, Raymond Farr Ranch, Center NE, NE, S. 48
    Blk. C-3, E. L. and R. R. Ry. Co., Donley County, Texas
    [approximately 6.5 miles north and 1 mile east of
    Clarendon], Clarendon fauna, Early Pliocene age. Obtained by
    W. W. Dalquest, on June 25, 1960.

    _Referred material._--Fragment of right lower mandible
    bearing m2, No. 11354 KU (see fig. 2), found about two feet
    horizontally distant from the holotype in the same stratum
    as the holotype and on the same date by the same collector
    (a staff member of the Department of Biology of Midwestern
    University, Wichita Falls, Texas).

[Illustration: FIG. 1. _Cynarctus fortidens_, No. 11353 KU (Midwestern
Univ. No. 2044). Lateral view of holotype × 1, and occlusal view of
check-teeth × 2.]

[Illustration: FIG. 2. _Cynarctus fortidens_, No. 11354 KU (Midwestern
Univ. No. 2045). Lateral view of right lower mandible and m2 × 1 and
oblique occlusal view of m2 × 2.]

    _Diagnosis._--Size large (see measurements); no accessory
    cusp between protocone and paracone of fourth upper
    premolar; first upper molar longer than broad and lacking
    cingulum on part of tooth lingual to protocone.

    _Comparisons._--From _Cynarctus crucidens_ Barbour and Cook
    (see page 225 of Two New Fossil Dogs of the Genus Cynarctus
    from Nebraska. Nebraska Geol. Surv., 4(pt. 15):223-227,
    1914; also pages 330 and 338 of Dental Morphologie of the
    Procyonidae with a Description of Cynarctoides, Gen. Nov.
    Geol. Ser. Field Mus. Nat. Hist., 6:323-339, 10 figs.,
    October 31, 1938) _C. fortidens_ differs in lacking, instead
    of having, an accessory cusp between the protocone and
    paracone of the fourth upper premolar and in lacking,
    instead of having, a cingulum on the part of P4 that is
    internal (lingual) to the protocone.

    _Remarks._--The lower jaw and its second molar seem to be
    from an individual significantly larger than the holotype.
    Possibly the lower jaw and upper jaw are from two species but
    the lower jaw probably is from a male and the upper jaw from
    a female of the same species.

    Reasons for regarding _Cynarctus_ as belonging to the family
    Canidae instead of to the family Procyonidae have been stated
    recently in detail by E. C. Galbreath (Remarks on
    _Cynarctoides acridens_ from the Miocene of Colorado. Trans.
    Kansas Acad. Sci., 59(3):373-378, 1 fig., October 31, 1956)
    and need not be repeated here. Although some uncertainty
    remains as to the familial position of _Cynarctus_, we favor
    Galbreath's view that the genus belongs in the family
    Canidae.

    The holotype of _Cynarctus crucidens_ is from Williams
    Canyon, Brown County, Nebraska. According to C. B. Schultz
    (_in litt._, December 6, 1961), Williams Canyon is a
    tributary of Plumb Creek; the upper part of the Valentine
    formation and the younger lower part of the Ash Hollow
    formation are exposed in Williams Canyon; which one of these
    formations yielded the holotype of _C. crucidens_ is unknown.

    On the basis of the correlation chart (Pl. 1 in Nomenclature
    and Correlation of the North American Continental Tertiary.
    Bull. Geol. Soc. Amer., 52(pt. 1):1-48, 1941) by H. E. Wood
    2nd _et al._, _C. fortidens_ and _C. crucidens_ are
    equivalent in age or _C. fortidens_ is the younger.

    The rounded summits of the principal cusps of the teeth of
    _C. fortidens_ suggests that it was mainly frugivorous
    instead of carnivorous--more frugivorous by far than the
    living gray fox, _Urocyon cinereoargenteus_, that is known to
    eat substantial amounts of fruits and berries. Indeed, no
    other canid that we know of has teeth so much adapted to a
    frugivorous diet as are those of _C. fortidens_. Its degree
    of adaptation to a frugivorous diet is more than in the
    procyonid genus _Nasua_ but less than in the procyonid genus
    _Bassaricyon_.

    _Measurements_ (of crowns) of _C. fortidens_.--P3-M1, length,
    25.8 (millimeters); P4-M1, 18.9; P3, length, 6.2; P3,
    breadth, 2.8; P4, length of outer border, 9.3; P4, breadth,
    7.05; M1, length, 9.7; M1, breadth, 9.3; m2, length, 10.3;
    m2, breadth, 6.6; depth of mandible at posterior end of m2,
    17; thickness of mandible, 7.1.


_Transmitted February 21, 1962._


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End of the Project Gutenberg EBook of A New Doglike Carnivore, Genus
Cynarctus, From the Clarendonian, Pliocene, of Texas, by E. Raymond Hall and Walter W.  Dalquest