Sunday, September 9, 2012

[Paleontology • 2011] Pamparaptor micros • A new small deinonychosaur (Dinosauria: Theropoda) from the Late Cretaceous of Patagonia, Argentina

Pamparaptor micros
Porfiri, Calvo & Santos, 2011

Here we report on a new small deinonychosaurian theropod, Pamparaptor micros gen. et sp. nov., from the Late Cretaceous of Patagonia, Argentina. Pamparaptor micros exhibits a pedal structure previously unknown among South American deinonychosaurians. The new material provides new evidence about the morphology and taxonomic diversity of Patagonian deinonychosaurs. Pamparaptor is the smaller non-avialae Patagonian deinonychosaur, probably with about 0.50-0.70 meters, long. The pedal construction resembles, that of Troodontid or basal Dromaeosaurids. Nevertheless, up to now, we considered Pamparaptor a peculiar Patagonian Dromaeosaurid with troodontid-like pes.
Key words: Argentina, Barreales Lake, Dromaeosauridae, Late Cretaceous, Patagonia, Unenlagiinae.

Etymology: Pampa, in honor to the Indian Pampas that lived in the central plain of Argentina; 
and raptor, robber in Greek; micros, for the small size of specimen.

During the last decade, the fossil record of deinonychosaurian theropods from Patagonia has notably increased. Up to now, the records of Deinonychosauria from Patagonia include Unenlagia comahuensis (Novas and Puerta 1997), Unenlagia paynemili (Calvo et al. 2004), Neuquenraptor argentinus (Novas and Pol 2005), Buitreraptor gonzalezorum (Makovicky et al. 2005) and Austroraptor cabazai (Novas et al. 2008).
Here we report on a new deinonychosaurian, Pamparaptor micros gen. nov sp. nov, collected from the Baal quarry, at the north coast of Barreales Lake, Neuquén, Argentina (Fig. 1). The specimen comes from the Portezuelo Formation, (Turonian-Coniacian), Neuquén Group, and it is represented by pedal elements. The new form is gracile and small, with about 0.50-0.70 meters, and its metatarsal construction is highly derived, resembling troodontids (Xu and Wang 2000). We offer here a brief description of this notable discovery.

Porfiri, Juan D.; Jorge O. Calvo and Domenica dos Santos. 2011. A new small deinonychosaur (Dinosauria: Theropoda) from the Late Cretaceous of Patagonia, Argentina. Anais da Academia Brasileira de Ciências. 83 (1): 109–116. doi:10.1590/S0001-37652011000100007