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Staurikosaurus

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Staurikosaurus
Temporal range: Late Triassic
Staurikosaurus with a Rhynchosaur.
Scientific classification
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Staurikosauridae
Genus:
Staurikosaurus

Colbert, 1970
Species
  • S. pricei Colbert, 1970 (type)

Staurikosaurus ("Lizard of the Southern Cross") is a genus of early dinosaur from the Late Triassic of Brazil.

Discovery

The first known specimen of Staurikosaurus was recovered from the Paleontological Site Jazigo Cinco of the Santa Maria Formation[1] in the geopark of paleorrota , Rio Grande do Sul, southern Brazil. The genus name refers to the star constellation "The Southern Cross", pictured in the coat of arms of Brazil and only visible in the southern hemisphere - when Staurikosaurus was described in 1970, it was unusual to find dinosaurs in the southern hemisphere. The specific name honours the Brazilian paleontologist Llewellyn Ivor Price. It was described by Edwin Harris Colbert, working at the American Museum of Natural History. The rarity of Staurikosaurus remains may be a result of it being uncommon while alive, or because it lived in an environment like a forest, where fossils rarely form.[1]

Description

Size comparison between Staurikosaurus and a human.
Staurikosaurus pricei.

Staurikosaurus was a small theropod from the late Triassic Period, 225 million years ago - specifically the Carnian age. It is one of the earliest dinosaurs that is known. At just 2 metres in length (6.5 ft),[1] 80 centimetres tall (31 in), and weighing just 30 kilograms (66 lb), Staurikosaurus was tiny in comparison to later theropods like Megalosaurus. Newer research seems to confirm that Staurikosaurus and the related Eoraptor and Herrerasaurus are definite theropods and evolved after the sauropod line had split from the Theropoda.

There exists very incomplete fossil record of Staurikosaurus, consisting most of the spine, the legs and the large lower jaw. However, dating from such an early period in the dinosaurs' history and being otherwise so primitive, most of Staurikosaurus' other features as being primitive also can be reconstructed. For example, Staurikosaurus is usually depicted with five toes and five fingers[1] - very simple features of an unspecialised dinosaur. However, since the skeletal structure of the legs is known, it can be seen that 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 tail would have been long and thin to balance the border - later sauropods had larger, shorter tails relative to their weight.

See also

Contemporaries

References

  1. ^ a b c d "Staurikosaurus." In: Dodson, Peter & Britt, Brooks & Carpenter, Kenneth & Forster, Catherine A. & Gillette, David D. & Norell, Mark A. & Olshevsky, George & Parrish, J. Michael & Weishampel, David B. The Age of Dinosaurs. Publications International, LTD. p. 45. ISBN 0-7853-0443-6.