Pliocene Antelopes of the Pronghorn Type

Abstract

The phylogeny of the Antilocapridae and reported species giving rise to Antilocapra americana has been a subject of considerable interest to paleontologists. The work of W. D. Matthew on the Merycodus of Miocene and Pliocene age, and that of J. C. Merriam on Illingoceros and Sphenophalos from the Pliocene, has increased considerably our knowledge of the probable line of descent of Antilocapra americana. The writer's attention was called by Merriam to a very interesting paper by E. H. Barbour and C. B. Schultz in which they describe a new genus and species, Proantilocapra platycornea, Barbour and Schultz, from the Lower Pliocene in Cherry County, Nebraska. However, no comparison or reference to the closely related genus Sphenophalos nevadanus Merriam was made. Proantilocapra, as figured, shows morphologic characters close to those of Sphenophalos.