Delotrochanter, Hunt, 2011

Hunt, Robert M., 2011, Evolution Of Large Carnivores During The Mid-Cenozoic Of North America: The Temnocyonine Radiation (Mammalia, Amphicyonidae), Bulletin of the American Museum of Natural History 2011 (358), pp. 1-153 : 74

Delotrochanter , new genus

TYPE SPECIES: Delotrochanter oryktes , new species.

INCLUDED SPECIES: Delotrochanter petersoni , new species; D. oryktes , new species; D. major , new species.

DISTRIBUTION: Mid- and late Arikareean of northwest Nebraska; latest Arikareean of Nebraska-Wyoming boundary in vicinity of the Niobrara River .

ETYMOLOGY: From the Greek, delos, for ‘‘evident,’’ and trochanter, ‘‘runner,’’ to emphasize the cursorial nature of these carnivores.

DIAGNOSIS: Distinguished from Temnocyon by absence of the m1 metaconid; by a centrally placed m2 protoconid and hypoconid; and by proportions of P4 and M1 (table 6, ratios A/B, C/D); from Mammacyon by a short, less elongate skull, by shorter broad p2–3 and less elongate m2 (ratio E/F); and from Rudiocyon by a more elongate m2 (ratio E/F). See tables 1–5.

DISCUSSION: The genus includes temnocyonines that abandon the plesiomorphic form of the cheek teeth and adopt a crushing durophagous dentition different from that of Mammacyon in proportions of the carnassial-molar battery. Delotrochanter petersoni appears to be a mid-sized ancestral species evolving to the large D. oryktes and the even larger D. major . The genus ranges in time from the midto latest Arikareean but is not certainly known in the early Arikareean interval.