The Pliocene pronghorn Hexobelomeryx fricki (Mammalia: Artiodactyla) from San Miguel de Allende, Guanajuato, central Mexico

Abstract

Hexobelomeryx fricki is recorded in the San Miguel de Allende graben since the late early Hemphillian to the Blancan III, from about 7.0 million years to 3.0 million years. The studied specimens were recovered from floodplain and point bar deposits of the informal Rancho Viejo beds. The mortality profile of the H. fricki teeth sample from the study area is an attritional one, with few juveniles and a large majority of old individuals. The estimated body mass of H. fricki specimens range from around 10 to 30 kilograms, according to their age at death. The record of this pronghorn in Guanajuato during the late early Hemphillian and the Blancan III, are the oldest and the youngest occurrence of the species in North America and extends its geographic distribution from northwestern Mexico to central Mexico during the late Hemphillian.