Phenacodus

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 : 38-39

Phenacodus cf. P. grangeri Simpson, 1935

HOLOTYPE: AMNH 17185 , right maxilla with M1–2 and labial fragment of M3 from Mason Pocket, Animas Formation , Colorado.

REFERRED SPECIMEN: RAM 7172, left m3 from RAM locality V94014 , member 4a (fig. 12B).

DESCRIPTION AND DISCUSSION: RAM 7172 is a slightly worn m3 whose paraconid is absent, but whose protoconid, metaconid, hypoconid, entoconid, and hypoconulid are large (fig. 12B). RAM 7172 is 12.87 mm in length and has trigonid and talonid widths of 8.72 mm and 7.99 mm, respectively.

RAM 7172 is almost identical to the m3 of USNM 21025, a dentary fragment with m3 from the Bison Basin. When describing P. bisonensis, Gazin (1956) noted the presence of a larger phenacodontid and described it as Phenacodus ? sp. (large), and included USNM 21025 in it. Later, Thewissen (1990) referred USNM 21025 to P. grangeri . RAM 7172 appears to represent P. grangeri , but m3s of P. grangeri cannot be reliably distinguished from P. intermedius based on size or morphology, or from P. magnus based on size (m3 of P. magnus is unknown) ( Thewissen, 1990). Thus, RAM 7172 is referred to Phenacodus cf. P. grangeri until more complete material of this taxon is recovered.

Phenacodus cf. P. vortmani Cope, 1880

HOLOTYPE: AMNH 4824 , left dentary with p4 and fragment of m1, roots of p3 and m3, and alveoli for p1–2 from Alkali Creek, Wind River Basin, Wyoming.

REFERRED SPECIMEN: RAM 7253, rp4 from RAM locality V200307, member 4d (fig. 12C).

DESCRIPTION: RAM 7253 is a slightly worn p4 (fig. 12C), that is 10.2 mm in length, with trigonid and talonid widths of 6.5 mm and 6.4 mm respectively. RAM 7253 has a large protoconid

Family PERIPTYCHIDAE Cope, 1882