Hemiauchenia

Hemiauchenia is a genus of laminoid camelids that evolved in North America in the Miocene period about 10 million years ago. This genus diversified and moved to South America in the Late Pliocene approximately 3 to 2 million years ago, as part of the Great American Biotic Interchange, giving rise to modern lamines. The genus became extinct at the end of the Pleistocene. The monophyly of the genus has been considered questionable, with phylogenetic analyses finding the geneus to paraphyletic or polyphyletic. The genus name is derived from the ἡμι- (hēmi-, "half"-) and αὐχήν (auchēn, "neck"). Species are specified using Latin adjectives or Latinised names from other languages. Remains of these species have been found in assorted locations around North America, including Florida, Texas, Kansas, Nebraska, Arizona, Mexico, California, Oklahoma, New Mexico, Oregon, Colorado, and Washington. The "large-headed llama", H. macrocephala, was widely distributed in North and Central America, with H. vera being known from the western United States and northern Mexico. H. minima has been found in Florida, and H. guanajuatensis in Mexico. Fossils of Hemiauchenia in South America are restricted to the Pleistocene and have been found in the Luján and Agua Blanca Formations of Buenos Aires Province and Córdoba Province, Argentina, the Tarija Formation of Bolivia, Pilauco of Osorno, Los Lagos, Chile and Paraíba, Ceará, and the Touro Passo Formation of Rio Grande do Sul, Brazil. Hemiauchenia paradoxa is suggested to have been a browser. Relatively low-crowned teeth (part of visible teeth ends close to gums) Large caniniform (canine-like) upper first premolar Retention of lower third premolar Named for Blancan Age stratum where typically found Shorter mandibular diastema (teeth-spacing between incisors and molars) than H. macrocephala and H.