Staurikosaurus

Staurikosaurus is a genus of Upper Triassic theropod dinosaurs found in Brazil.Nesbitt S.J. et al. 2009. A complete skeleton of a late Triassic saurischian and the early evolution of dinosaurs. Science 326:1530-1533. It was a small, lightly built carnivore.Staurikosaurus. In: Dodson, Peter et al. The age of dinosaurs. Publications International, p45 .

The rarity of Staurikosaurus remains may be a result of it being uncommon while alive, or because it lived in an environment such as a forest, where fossils rarely form.

Description

At just ,Grillo O.N. and Azevedo S.A.K. 2011. Recovering missing data: estimating position and size of caudal vertebrae in Staurikosaurus pricei Colbert, 1970. Annals of the Brazilian Academy of Sciences, 80 centimetres tall (31 in), and weighing just 30 kilograms (66 lb), Staurikosaurus was small in comparison to later theropods like Megalosaurus. Staurikosaurus and the related Herrerasaurus are definitely theropods and evolved after the sauropod line had split from the theropods.

The fossil record of Staurikosaurus is poor, but the skeletal structure of the legs is known. Staurikosaurus was a quick runner for its size. It also had just two vertebrae joining the pelvis to the spine, a distinctly primitive arrangement.

The available teeth for Staurikosaurus strongly suggest a carnivorous diet.

 Tail 
The tail of Staurikosaurus was relatively long (with more than 40 vertebrae) compared to the rest of its body and was held straight and off the ground as it ran.  The rear part of Staurikosaurus's tail is stiffened by features of the tail vertebrae.  Ostrom thought this was a dynamic stabilizer to help balance while leaping and running.Ostrom J.H. 1969. Osteology of Deinonychus antirrhopus, an unusual theropod from the Lower Cretaceous of Montana. Peabody Museum Bulletin 30:1-165

 References 

 Other websites 
 Dinosaurs of Rio grande do Sul. 

Category:Triassic dinosaurs
Category:Dinosaurs of South America
Category:Theropods