New evidence on deinonychosaurian dinosaurs from the Late Cretaceous of Patagonia

NOVAS, F.E.; POL, D.

NATURE

Nature Publishing Group

Lugar: London; Año: 2005 vol. 433 p. 858 - 861

0028-0836

Most that is known about deinonychosaurian evolution is based on discoveries from North America and Asia. Except for Unenlagia comahuensis and some fragmentary remains from northern Africa, no other evidence was available about deinonychosaurian diversity in Gondwana. Here we report on a new Late Cretaceous maniraptoran, Neuquenraptor argentinus gen. et sp. nov., representing the first uncontroversial evidence of a deinonychosaurian theropod in the Southern Hemisphere. Neuquenraptor combines an arctometatarsalian condition of the foot with a trenchant claw on the second pedal digit. Although this set of features may suggest troodontid affinities, character analysis supports Neuquenraptor as a basal member of Dromaeosauridae, sharing with other basal dromaeosaurids the presence of proximally pinched third metatarsal and a ginglymoid distal end of the second metatarsal. This suggests that dromaeosaurids were probably distributed worldwide at least, by the beggining of the Cretaceous. The new evidence indicates that Cretaceous theropod faunas from the Southern continents were more similar to those of the Northern landmasses than previously thought.