New theropod: Austroraptor

[jigruiz@unizar.es]

http://news.nationalgeographic.com/news/2008/12/081217-new-raptor-missions.html

The paper is:

Fernando E. Novas, Diego Pol, Juan I. Canale, Juan D. Porfiri and  
Jorge O. Calvo. in press. A bizarre Cretaceous theropod dinosaur from  
Patagonia and the evolution of Gondwanan dromaeosaurids. Proc. R. Soc.  
B doi:10.1098/rspb.2008.1554

The abstract:

Fossils of a predatory dinosaur provide novel information about the  
evolution of unenlagiines, a poorly known group of dromaeosaurid  
theropods from Gondwana. The new dinosaur is the largest dromaeosaurid  
yet discovered in the Southern Hemisphere and depicts bizarre cranial  
and postcranial features. Its long and low snout bears numerous,  
small-sized conical teeth, a condition resembling
spinosaurid theropods. Its short forearms depart from the  
characteristically long-armed condition of all dromaeosaurids and  
their close avian relatives. The new discovery amplifies the range of  
morphological disparity among  unenlagiines, demonstrating that by the  
end of the Cretaceous this clade included large, short-armed forms  
alongside crow-sized, long-armed, possibly flying representatives. The  
new dinosaur is the youngest record of dromaeosaurids from Gondwana  
and represents a previously unrecognized lineage of large predators in  
Late Cretaceous dinosaur faunas mainly dominated by abelisaurid  
theropods.

Keywords: Theropoda; Dromaeosauridae; Unenlagiinae; Cretaceous; South  
America; forelimb

And some info on the critter:

(a) Systematic palaeontology

Theropoda (Marsh 1884)
Coelurosauria (Huene 1920)
Deinonychosauria (Colbert & Russell 1969)
Dromaeosauridae (Matthew & Brown 1922)
Unenlagiinae (Bonaparte 1999)
Austroraptor cabazai, new taxon.

(b) Holotype
Specimen number MML-195 consists of right frontal and postorbital,  
lacrimals, maxillae and dentaries with teeth, right surangular and  
prearticular, cervicals 3, 5, 6, 7 and 8, dorsals 2 and 4, isolated  
ribs and gastralia, right humerus, manual ungual of digit III, left  
pubic shaft, left femur, and right tibia, astragalus, calcaneum,  
metatarsal III and pedal phalanges I-2, II-2, III-4 and IV-2 (figure 1).

(c) Etymology
Austroraptor, from austral in reference to southern South America, and  
raptor, thief; and cabazai, in honour to the late He´ctor Cabaza,  
founder of the Museo Municipal de Lamarque.

(d) Locality and horizon
Allen Formation (Campanian?Maastrichtian; Martinelli & Foriasepi  
2004), Bajo de Santa Rosa (408030 2800 S, 668480 0300 W),  
approximately 90 km southwest of Lamarque town, R?o Negro Province,  
Argentina. Theropod dinosaurs collected from the Allen Formation  
include the abelisaurid Quilmesaurus curriei (see Juarez Valieri et  
al. 2007), a yet unnamed alvarezsaurid (Agnol?´n et al. 2006), and  
indeterminate tetanurans (Coria & Salgado 2005).

(e) Diagnosis
A large dromaeosaurid with the following combination of characters  
that distinguish it from other members of this group (autapomorphies  
marked with an asterisk): lacrimal highly pneumatized, with descending  
process strongly curved rostraly, and caudal process flaring out  
horizontally above orbit (differing from Laurasian dromaeosaurids, but  
unknown for other unenlagiines); postorbital lacking dorsomedial  
process for articulation with the frontal, and with squamosal process  
extremely reduced (differing from Laurasian dromaeosaurids, but  
unknown for other unenlagiines); maxillary and dentary teeth small,  
conical-shaped, devoid of serrations and flutted (as in Buitreraptor);  
humerus short, representing slightly less than 50 per cent of femur  
length (a smaller ratio than in other dromaeosaurids and paravians);  
pedal phalanx II-2 transversely narrow, contrasting with the extremely  
robust phalanx IV-2 (differing from other dromaeosaurids, including  
unenlagines, but resembling the condition of advanced troodontids).


-------------------------------------------
Jose Ignacio Ruiz-Omeñaca
Museo del Jurásico de Asturias (MUJA)
E-33328 Colunga, Spain
www.museojurasicoasturias.com
www.aragosaurus.com
-------------------------------------------