Piatnitzkysaurus: An Early Neovenatorid from South America

Piatnitzkysaurus is a Middle Jurassic theropod dinosaur from Argentina, measuring approximately 4.5 meters in length. As one of the most significant Middle Jurassic theropod discoveries in South America, it demonstrates the early radiation of coelurosaurs in the Southern Hemisphere. Its body structure exhibits transitional anatomical features between primitive ceratosaurs and advanced coelurosaurs. With relatively long forelimbs and three functional fingers on each hand, Piatnitzkysaurus provides evidence that theropod dinosaurs in South America were already diversifying during the Middle Jurassic, laying the groundwork for later groups such as Abelisauridae and Megalosauroidea.