Generic Identification of the Pleistocene Antelope from Rancho La Brea

Abstract

When the diminutive antelope from the Pleistocene asphalt of Rancho La Brea was originally described by Taylor (1911), comparison with Matthew's genus Capromeryx was of necessity limited in scope. Jaw and skeletal remains of the former were available, but only an incomplete ramus with full cheek-tooth dentition comprised the Nebraskan type. Indeed, no adequate comparison between the lower cheek teeth of these forms could be made, for whereas only milk teeth are present in the one form, permanent teeth occur in the other. Assignment of the Rancho La Brea species to Capromeryx was therefore tentatively made by Taylor, and was in part based upon the fact that the Californian form and Capromeryx showed a similar size relation to the modern pronghorn antelope. At the time of Taylor's description, Capromeryx was regarded as coming from Pleistocene beds in Nebraska. Subsequent authors, following Chandler (1916), definitely regarded the extinct asphalt species as belonging to the genus Capromeryx. The correctness of this determination was first questioned by Hesse (1935). Later, Stirton (1938) discussed more fully the reasons why the Californian and Mexican species could not be assigned to Capromeryx. A restudy of the material of the small antelope from Rancho La Brea has convinced the writer of the soundness of the views presented by Hesse and Stirton. The species minor is therefore placed in a new genus.