Cynelos malasi: An Eurasian Bear Dog in Miocene Neogene Southern California

A skull of the immigrant Eurasian beardog Cynelos (Carnivora, Amphicyonidae) from the early Miocene of southern California

Authors:

Hunt et al

Abstract:

At ∼23 Ma, large amphicyonid carnivorans participated in the initial Neogene mammal migration passing though the Bering filter en route to North America. Among the migrants were the amphicyonines Cynelos and Ysengrinia, first appearing in early Miocene sediments of the upper Arikaree Group in Nebraska and Wyoming, having entered the New World with chalicotheres, small cervoids, and the cursorial rhinoceros Menoceras. Early representatives of these immigrant carnivores had not, until recently, been recovered from localities along the Pacific coastal corridor of western North America. Here we report the discovery of a unique skull that establishes the presence of an early Neogene species of Cynelos (C. malasi, sp. nov.) in coastal southern California. The skull shares craniodental features with early Miocene species of the genus in Europe. Dentition (P4-M1-M2) and cranial morphology of Cynelos malasi compare with C. helbingi (southern Germany) and C. lemanensis (France, Germany) but uniquely combine size and occlusal detail to preclude assignment to these species. Cynelos malasi is assigned a latest Arikareean (Ar4) age in the North American Land Mammal Age (NALMA) chronology. By the early Miocene, species of Cynelos had dispersed from western Europe to northern Africa and into western North America. Whether the taxon arrived in North America by following a coastal southern Asian route or by Palaearctic dispersal is unconfirmed. Given the similarity between North American and European species of Cynelos, we suspect that the genus spanned Asia during the early Miocene.