First record of a complete humerus of Agriotherium (mammalia-ursidae) from the early-late Hemphillian of Zacatecas, Mexico

  • Oscar Carranza-Castañeda Centro de Geociencias, Universidad Nacional Autónoma de México, Campus Juriquilla, 76230, Querétaro, Querétaro, Mexico.
  • Xiaoming Wang Department of Vertebrate Paleontology, Natural History Museum of Los Angeles, 900 Exposition Blvd, Los Angeles, CA 90007, USA. Institute of Vertebrate Paleontology and Paleoanthropology, 142 Xizhimenwai Dajie, Western District Beijing 100044, China.
Keywords: Ursidae, Agriotherium, carnivore, humerus, early-late Hemphillian, Juchipila basin, Zacatecas, Mexico


A complete humerus referred to Agriotherium is described, collected from early-late Hemphillian deposits from Zacatecas. Agriotherium is widely represented by isolated molars, mandibles, and maxillae in early-late Hemphillian faunas of Eurasia and North America. In the literature, postcranial elements are scarce and briefly described with little detail. The greatest diversity is known from the Langebaanweg quarry in South Africa; however, the only complete specimen is from Mexico. The proximal end is described, and the humerus shares similarities with the description of the distal end from South Africa, in which the medial epicondyle and crest of the lateral epicondyle are reduced, which can be considered as a limitation in the hunting of larger prey for food. This implies that Agriotherium was not strictly carnivorous but was a predator-scavenger with an omnivorous diet that included plants and fruits.

SPECIAL SECTION "20 years of the Centro de Geociencias, UNAM"