Historical biogeography of trilophodont gomphotheres (Mammalia, Proboscidea) reconstructed applying dispersion-vicariance analysis

ALBERDI, MARÍA T.; PRADO, JOSÉ L.; ORTIZ-JAUREGUIZAR, EDGARDO; POSADAS, PAULA; DONATO, MARIANO

4th European Meeting on the paleontology and stratigraphy of Latin America

Instituto Geológico y Minero de España

Lugar: Madrid; Año: 2007; p. 9 - 14

The trilophodont gomphotheres are a monophyletic group of Proboscidea characterized by one synapomorphy, i.e., wear drawing trefoils on occlusal surface of teeth. The wearing of the tooth occlusal surface gave rise to draw trefoils. This draw varied from single to complicate, but all genera studied here present drawing trefoils. The Gomphotheriidae family is considered a long-living ancestral stock that gave origin to a succession of other groups. According to Lambert (1996), North America played a significant role in the biogeography and diversity of the gomphotheres. From the Early Miocene to the Pleistocene, this continent received numerous immigrant taxa from the Old World via Beringia (Lambert, 1996). Gomphotheres diversity also reached its peak during this span, with six known genera from the late Clarendonian to the Early Hemphillian and reduced in number during the Late Hemphillian (Webb, 1983). The gomphotheres were widespread throughout South America from the ?Late Pliocene-Early Pleistocene, and underwent a total extinction at the Pleistocene/Holocene boundary (Prado et al., 2005; Reguero et al., 2007).  The objective of our paper was to analyse the distributional patterns of trilophodont gomphotheres, applying an event-based biogeographic method: dispersal-vicariance analysis (DIVA) . Additionally, we have attempted to interpret the biogeographical evolution of this family in the context of the geologic evolution of the continents they inhabited during the Late Neogene.