title: New evidence on deinonychosaurian dinosaurs from the Late Cretaceous of Patagonia.
abstract: Most of what is known about the evolution of deinonychosaurs (that is, the group of theropods most closely related to birds) 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 on deinonychosaurian diversity in Gondwana. Here we report a new, Late Cretaceous member of the clade, Neuquenraptor argentinus gen. et sp. nov., representing uncontroversial evidence of a deinonychosaurian theropod in the Southern Hemisphere. The new discovery demonstrates that Cretaceous theropod faunas from the southern continents shared greater similarity with those of the northern landmasses than previously thought. Available evidence suggests that deinonychosaurians were probably distributed worldwide at least by the beginning of the Cretaceous period. The phylogenetic position of the new deinonychosaur, as well as other Patagonian coelurosaurian theropods, is compatible with a vicariance model of diversification for some groups of Gondwanan and Laurasian dinosaurs.
authors.affiliation: CONICET, Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Av. Angel Gallardo 470, Buenos Aires 1405, Argentina. fernovas@yahoo.com.ar
authors.forename: Fernando E
authors.initials: FE
authors.lastname: Novas
authors.forename: Diego
authors.initials: D
authors.lastname: Pol
mesh_terms: D001118:Argentina; D044822:Biodiversity; D005075:Biological Evolution; D001842:Bone and Bones / Q000033:anatomy & histology; D025061:Dinosaurs / Q000033:anatomy & histology / Q000145:classification*; D005580:Fossils; D049690:History, Ancient; D010802:Phylogeny