Paleocene (Danian) chelid turtles from Patagonia, Argentina: taxonomic and biogeogragraphic implications.

PAULA BONA

NEUES JAHRBUCH FUR GEOLOGIE UND PALAONTOLOGIE-MONATSHEFTE

Lugar: Stuttgart; Año: 2006 p. 303 - 323

0028-3630

Three chelid turtles are reported from the Salamanca Formation (Maastrichtian-Danian) of Argentina. On the basis of new material recovered at Cerro Hansen (Chubut province, Argentina), two new taxa of chelid turtles are described. Salamanchelys palaeocenica new species is probably closely related to the Phrynops s. l. complex;  Comtuschelys fragilis new species, has uncertain  affinities among the Chelidae. The extant genus Hydromedusa is also represented by Hydromedusa cf. H. casamayorensis, whose record in the Salamanca Formation extends its geological distribution back to the Danian. The presence of these chelid taxa in the Patagonian Danian supports the hypothesis of an early differentiation and diversification of chelids on Gondwanan landmasses.