title: A new Mammutidae (Proboscidea, Mammalia) from the Late Miocene of Gansu Province, China.
abstract: The "Yanghecun specimen", a proboscidean specimen represented by a mandible from Miocene of China and previously described as Gomphotheriidae, is here reviewed and described as a new genus and species of Mammutidae: Sinomammut tobieni. This taxon is a longirostrine mastodon, lacking lower tusks, and bearing a wide last molar with oblique and non-inflated lophids, broad transverse interlophids, and yoke-like wear figures. Phylogenetic analysis of Mammutidae based on dental and mandibular features recovered S. tobieni as sister group of the mastodon Mammut. The longirostrine condition and the well-developed lower incisors seem to be primitive for Mammutidae, while the brevirostry is the derived condition, probably emerged during the middle Miocene (12-11 Mya). However, two derived conditions are recognized to the lower tusks: the absence of lower tusks (S. tobieni) and the occasional presence of vestigial lower tusks (Mammut).
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas, Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Dimila
authors.initials: D
authors.lastname: Mothé
authors.affiliation: Laboratório de Mastozoologia, Departamento de Zoologia, Universidade Federal do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Leonardo S
authors.initials: LS
authors.lastname: Avilla
authors.affiliation: Gansu Industrial Occupational Technology College, Tianshui, China.
authors.forename: Desi
authors.initials: D
authors.lastname: Zhao
authors.affiliation: Gansu Provincial Museum, Lanzhou, China.
authors.forename: Guangpu
authors.initials: G
authors.lastname: Xie
authors.affiliation: Tianjin Museum of Natural History, Tianjin, China.
authors.forename: Boyang
authors.initials: B
authors.lastname: Sun
mesh_terms: D000818:Animals; D002681:China; D005580:Fossils; D008334:Mandible / Q000033:anatomy & histology*; D056666:Mastodons / Q000033:anatomy & histology* / Q000145:classification; D010802:Phylogeny