A new specimen of Camelops hesternus (Artiodactyla, Camelidae) from Valsequillo, Puebla, Mexico, with comments about their dietary preferences and the population density of the species

Abstract

Camelidae is one of the most diverse and successful artiodactyl families, with a long geological history and wide geographical range in North America. Camelops hesternus was the one of last camelids in North America during the Pleistocene (Rancholabrean) and its remains have been found from Alaska south into Mexico. Here, we describe a new specimen of this species based on a complete mandible from the Late Pleistocene sediments of the Cerro Grande de la Mesa Calderón monogenetic volcano in the Valsequillo Basin, Puebla, central Mexico. A mesowear analysis of the dentition indicates wear in the new specimen to be similar to that of the Klipspringer, Oreotragus oreotragus, indicating a browsing diet. The population density of C. hesternus in the Valsequillo Basin was estimated using a differential non-linear equations mathematical model under three scenarios (stress, optimal, and abundance conditions) a indicating the range in its population density of 0.51–1.8 ind/km2, and this species was not abundant in the region. Despite the low population density C. hesternus has been reported in Mexico from 27 Pleistocene localities, with a geographic range from north (29°40′ latitude, Sonora) to south (16°14′ latitude, Chiapas) at an altitude range of 0–200 m asl in Baja California Sur to 2500 m asl in the Trans-Mexican Volcanic Belt.