Osteology of the unenlagiid theropod Neuquenraptor argentinus from the Late Cretaceous of Patagonia

BRISSÓN EGLI F.; FERNANDO E. NOVAS; AGNOLÍN F.; ALEXIS M. ARANCIAGA ROLANDO

ACTA PALAEONTOLOGICA POLONICA

INST PALEOBIOLOGII PAN

Lugar: Varsovia; Año: 2017 vol. 62 p. 549 - 562

0567-7920

Neuquenraptor argentinus was described as the first undoubted deinonychosaurian theropod from Gondwana. Theonly known specimen is represented by a fragmentary skeleton, including a nearly complete foot, coming from LateCretaceous beds of Neuquén Province, Patagonia, Argentina. Neuquenraptor was later considered as belonging to theSouthern Hemisphere paravian clade Unenlagiidae, and proposed as a junior synonym of Unenlagia comahuensis. Theaim of the present paper is to include a detailed anatomical description of Neuquenraptor (up to the date only known bya preliminary description). Comparisons with other paravians, especially unenlagiids, resulted in the finding of charactersthat may be considered as diagnostic of Unenlagiidae (e.g., scar-like fourth trochanter of femur, metatarsal II withtongue-shaped process over the caudal surface of metatarsal III, well-developed convex longitudinal plantar crest ofmetatarsal IV). Furthermore, comparisons between Neuquenraptor and Unenlagia are carried out with the aim to evaluatethe possible synonymy between these taxa. These comparisons indicate that at least two similar-sized unenlagiidswere present on the Portezuelo Formation. However, in concordance with previous authors, we are not able to supportnor dismiss the possible synonymy between Unenlagia and Neuquenraptor. Additional findings of unenlagiid fossilsfrom the Portezulo Formation will help to clarify the taxonomic status of these taxa.