Rudiocyon, 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 : 54

Rudiocyon , new genus

TYPE SPECIES: Rudiocyon amplidens , new species.

INCLUDED SPECIES: Only the type species.

DISTRIBUTION: Early or mid-Arikareean of Oregon.

ETYMOLOGY: From the latinized Greek, kyon, for ‘‘dog,’’ and for Rudio Creek, the locality in north-central Oregon where the holotype was discovered.

DIAGNOSIS: Differs from Temnocyon by absence of the m1 metaconid; from Mammacyon and Delotrochanter by a small, short m2 relative to m1 (table 6, ratio E/F,1.9); and from Delotrochanter by a narrow, compressed p4 (not posteriorly broad). See tables 1–2.

DISCUSSION: The genus includes a single species represented by a partial mandible with massive teeth (p4–m2) that define the taxon. A small m 2 in Rudiocyon (table 6, ratio E/F,,1.9) precludes assignment to Mammacyon (table 6, ratio E/F, 1.57–1.6), a genus defined by a large, elongate m2. Nonetheless, the genus may have evolved from an earlier less derived species that gave rise to both Mammacyon and Rudiocyon . Similarity to cheek teeth of T. ferox suggests a possible alternative derivation for R. amplidens . Rudiocyon amplidens is considered somewhat younger than the age of the Deep Creek tuff (27.9 ± 0.57 Ma); the probable site of collection occurs 10–15 m above a local ash on Rudio Creek identified as a correlative of the Deep Creek tuff.