[D] Skorpiovenator bustingorryi [sG] [T]
Canale, Scanferla, Agnolin & Novas 2008
Cretaceous Late Cenomanian Turonian
Saurischia Theropoda Abelisauridae [Carnotaurinae] [Brachyrostra]
Huincul Formation, Bustingorry’s farm, 3 km NWof Villa El Chocón, Neuquén Province, NW Patagonia, Argentina
A nearly complete skeleton of the new abelisaurid Skorpiovenator bustingorryi is reported here. The holotype was found in Late Cenomanian–Early Turonian outcrops of NW Patagonia, Argentina. This new taxon is deeply nested within a new clade of South American abelisaurids, named Brachyrostra. Within brachyrostrans, the skull shortening and hyperossification of the skull roof appear to be correlated with a progressive enclosure of the orbit, a set of features possibly related to shock-absorbing capabilities.
Moreover, the development of horn-like structures and differential cranial thickening appear to be convergently acquired within Abelisauridae. Based on the similarities between Skorpiovenator and carcharodontosaurid tooth morphology, we suggest that isolated teeth originally referred as post-Cenomanian Carcharodontosauridae most probably belong to abelisaurids. The specimen was found in fluvial sandstones with intercalated mudstones, belonging to the lower levels of the Huincul Formation.
The generic name derives from the Latin words skorpios (scorpion) and venator (hunter) because of the abundance of living scorpions moving around the excavation. The specific name honours the late Manuel Bustingorry, owner of the farm where the specimen was excavated.
MMCH-PV 48 (Museo Municipal “Ernesto Bachmann”, Villa El Chocón, Neuquén, Argentina): an articulated skeleton (Fig. 1b, c) represented by an almost complete skull and mandibles and most of the postcranial bones, lacking the right forearm and the distal half of the tail.
Skorpiovenator is distinguished from other abelisaurids on the basis of the following unique traits: ascending process of maxilla homogeneously wide rostrocaudally, maxillary horizontal ramus dorsoventrally deep with subparallel dorsal and ventral margins, maxilla/jugal contact subvertical, 19 maxillary teeth, lacrimal rostrally projected and with well-developed suborbital process, quadratojugal with pronounced caudal notch, dentary with caudoventral process bifurcated to receive rostral end of angular, and angular with rostral end dorsoventrally deep to fit between splenial and prearticular.