Ruminants (Artiodactyla, Ruminantia) include the chevrotain, Family Tragulidae, and five families within Pecora, including the Family Bovidae. Based on horn core characteristics, the earliest member of the Bovidae is Eotragus (Boselaphini) from the early-middle Miocene of Europe and Pakistan (Solounias et al. 1995; Gentry 2000). Simpson (1945) and Vrba and Schaller (2000) suggest that classification of Bovidae is among the most difficult of all mammalian families. As a monophyletic group, the modern bovids can be divided into five or six subfamilies, including the monophyletic Caprinae (Gentry 1992; Gatesy et al. 1997; Vrba and Schaller 2000). The Caprinae include the wild sheep and true goats (Caprini), the muskoxen (Ovibovini), and the mountain goats, gorals, serows, and chamois of the non-monophyletic group ‘Rupicaprini’ (Gentry 1992). See Gentry (1992) and Grubb (2001) for discussions concerning the utility of ‘Rupicaprini’ and ‘Naemorhedini’; here we use ‘Rupicaprini’ and ‘rupicaprine’ in quotes to designate confusion created by non-monophyly and the need for further work within the group.
North America today has a number of endemic and Holarctic species of bovids including the bison (Bison), muskox (Ovibos), wild sheep (Ovis), mountain goat (Oreamnos), along with many extinct forms (Kurtén and Anderson 1980). The timing of the arrival of bovids from Asia is still inadequately understood. Here we present a new species of Caprini from the early Pliocene, Blancan NALMA (North American Land Mammal Age), deposits of Panaca, Nevada, USA. This species likely is the earliest caprine to enter North America.