ARCTOCYONIDAE, Murray, 1866

Lofgren, Donald, Mckenna, Malcolm, Honey, James, Nydam, Randall, Wheaton, Christine, Yokote, Bryan, Henn, Lexington, Hanlon, Whitney, Manning, Stephen & Mcgee, Carter, 2014, New records of eutherian mammals from the Goler Formation (Tiffanian, Paleocene) of California and their biostratigraphic and paleobiogeographic implications, American Museum Novitates 2014 (3797), pp. 1-60 : 24

ARCTOCYONIDAE ?

REFERRED SPECIMEN: RAM 9660, a p2, p3, P2, or P3 from RAM locality V200613, member 4b ( fig. 6H ).

DESCRIPTION: RAM 9660 is a large premolar with slightly crenulated enamel that is 5.75 mm in length and 4.30 mm in width if the long axis of the tooth is its anterior-posterior orientation. RAM 9660 has a large and swollen anterior cusp that is connected by a pair of posteriorly directed cristae that terminate at small cusps on the tooth margin ( fig. 6H ). These low cusps are connected by a weakly developed cingulum or cingulid that forms the posterior (?) edge of the tooth.

DISCUSSION: RAM 9660 probably indicates the presence of an additional eutherian from the Goler Formation. RAM 9660 may be an arctocyonid, but this is uncertain, as is which tooth site RAM 9660 represents. Another possibility is that RAM 9660 represents an upper premolar of Goleroconus .

Order CONDYLARTHA Cope, 1881a

Family HYOPSONDONTIDAE Trouessart, 1897

Figures

FIGURE 6. Dentition of oxyclaenids and arctocyonids. A. Occlusal view of RAM 9041, right m1 of Thryptacodon sp. from RAM locality V200510. B. Occlusal view of RAM 15622, right dentary fragment with talonid of p4, and m1–2 of Mimotricentes tedfordi from RAM locality V201014; C. oblique labial view of RAM 15622. D. Occlusal view of RAM 9670, left dentary fragment of Mimotricentes tedfordi with damaged m1 and base of p4 from RAM locality V200510. E. Occlusal view of RAM 6928, right dentary fragment of Mimotricentes tedfordi with m3 talonid and base of trigonid from RAM locality V200001. F. Occlusal view of RAM 9040, right M1 of Lambertocyon cf. L. gingerichi from RAM locality V200001. G. Occlusal view of RAM 9043, left p3 fragment of Lambertocyon cf. L. gingerichi from RAM locality V200001. H. Occlusal view of RAM 9660, premolar of undetermined arctocyonid from RAM locality V200613.