Staurikosaurus

Staurikosaurus is a genus of basal saurischian dinosaur that lived during the Late Triassic period in what is now Brazil. It is one of the earliest known dinosaurs. The only known species is Staurikosaurus pricei. The name Staurikosaurus means "staurikos lizard" and was named after the Staurikos, a constellation representing the Southern Cross. The species name honors the paleontologist Luiz Emílio de Souza Price, who discovered the fossil.

The fossil remains of Staurikosaurus were found in the Santa Maria Formation of the Rio Grande do Sul state. This formation is significant as it has yielded some of the oldest dinosaur fossils discovered. Staurikosaurus lived in a tropical environment alongside other early reptiles.

Staurikosaurus was a small, bipedal carnivore. It is estimated to have been about 2 meters (6.6 feet) long. Its anatomy shows it was a primitive dinosaur, likely an early theropod or a very basal dinosauriform close to the origin of true dinosaurs. Key features include its relatively long tail and the structure of its hip and hind limbs, indicative of agile movement.

The discovery of Staurikosaurus has been crucial in understanding the early evolution and diversification of dinosaurs during the Triassic period. Its primitive characteristics help paleontologists place it within the dinosaur family tree and trace the development of dinosaur lineages.