Skorpiovenator ("scorpion hunter") is a genus of abelisaurid theropod dinosaur from the Early Cretaceous (Albian) Huincul Formation of Argentina. The sole species of Skorpiovenator, S. bustingorryi, was named in honour of Manuel Bustingorry, the late owner of the farm on which the type specimen was discovered. Formally described in 2009, the type specimen is one of the most complete and informative abelisaurids yet known, described from a nearly complete and articulated skeleton. A tibia fragment was assigned to Skorpiovenator in 2022. Skorpiovenator was a fairly large abelisaurid. What is preserved of the type specimen measures 4.35 m (14.3 ft) in length. Based on the anatomy of close relatives, it may have been between 6–6.2 m (19.7–20.3 ft) long in life, and may have weighed a little under 900 kilograms (2,000 lb). Its skull was short and blunt, and somewhat resembled that of Carnotaurus. Its bone texture was rugose, even by the standards of other abelisaurids, which indicates the presence of large facial scales. The skull is also covered in small pits called foramina, which suggests a strong degree of facial sensitivity.
Discovery and naming The type specimen of Skorpiovenator bustingorryi (MMCH-PV 48K) was discovered in 2005 by Juan Ignacio Canale and Agustín Scanferla. At the time, they were field prospecting, on a farm owned by Manuel Bustingorry, 3 km (1.9 mi) northwest of Villa El Chocón, in the Neuquén Province. The specimen consists of a nearly complete skeleton, missing only part of the nasals and premaxillae, parts of the pelvic girdle, sections of the tail, and most of the forelimb elements. Given that it was preserved in articulation, the specimen was extracted in a single plaster jacket to lower the risk of its destruction. The strata from which MMCH-PV 48K was recovered belong to the lower part of the Huincul Formation in Patagonia, which was originally dated to the late Cenomanian stage, about 95 million years ago, though is now dated to the late Albian, about 106.2 million years ago. After its extraction, MMCH-PV 48K was relocated to the Ernesto Bachmann Paleontological Museum of Villa El Chocón, Patagonia, Argentina. The skull was separated from the cervical (neck) vertebrae during preparation to enable detailed analysis including computed tomography (CT) scans. In a paper physically published in 2009 (released as an advanced publication online the year before), Canale, Scanferla, Federico L. Agnolin and Fenando E. Novas formally described the specimen, assigning to it the binomial name of Skorpiovenator bustingorryi. The generic name derives from the Latin words skorpios ("scorpion") and venator ("hunter"), referring to its nature as a predator and the abundance of scorpions at the dig site. The specific name honours Manuel Bustingorry, who had died by the time the paper was released. In naming Skorpiovenator, Canale and colleagues erected a new abelisaurid clade, Brachyrostra, to which it was assigned. In 2022, the proximal (far) end of a right tibia, MMCh-PV255, was assigned to Skorpiovenator.
Description
Body size The preserved length of the excavated Skorpiovenator skeleton, measured from the premaxilla to the 12th caudal (tail) vertebra is 4.35 m (14.3 ft). Since it lacks most of the tail, precise length measurements are currently impossible, but it has been estimated to have grown up to 6–6.2 m (19.7–20.3 ft) long and weighed up to 891 kilograms (1,964 lb).
Skull and dentition
The skull of Skorpiovenator, measured from the premaxilla to the quadrate, measured 54.1 cm (21.3 in) in length. It was fairly short and blunt, similar to that of Carnotaurus, though was shorter and deeper than those of Abelisaurus and Majungasaurus. Much of the bone surface, especially on the top of the skull, is covered in small foramina, suggesting extensive innervation from the trigeminal nerve. This suggests the presence of sensitive facial tissues, akin to those seen in many other theropods, including the related Majungasaurus. The antorbital fossa is less developed than in other abelisauroids. The postorbital was large, and intersected the orbit (eye socket), to the point where it almost contacted the lacrimal on the opposite side. Consequently, the orbit had a distinctive "keyhole" shape, similar to that of Carnotaurus and the giant coelurosaur Tyrannosaurus rex. The dorsal border of the postorbital was inflated and well-ornamented, similar to that of Ekrixinatosaurus. The bone texture of Skorpiovenator's skull was very rugose, even when compared with other abelisaurids. The rugosities of the snout are hummocky, which are osteological correlates for scales, and the overall pattern of cranial ornamentation is almost identical to that of Rugops. Phylogenetic analysis suggests that the ornamentation observed on the frontal bones, also seen in Ekrixinatosaurus, may be apomorphic for abelisaurids more derived than Arcovenator, and an extreme version may account for the prominent horns seen in Carnotaurus. Each of Skorpiovenator's premaxillae bore four teeth, whereas each maxilla bore 19 teeth, more than in any other abelisaurid. The shape of the tooth crowns is similar to other abelisaurids. They exhibit enamel wrinkles and serrations, and in those regards, resemble the teeth of carcharodontosaurids. The right dentary appears to have housed 21 teeth.
… excerpt ends here. Continue reading the full article.
