Herrerasaurus ischigualastensis

Herrerasaurus ischigualastensis was a primitive carnivorous dinosaur that lived during the Late Triassic Period, approximately 228.7 to 199.6 million years ago. Fossils of this dinosaur have been found in Argentina.1

Key Characteristics:

• Size: Herrerasaurus reached about 3 meters (10 feet) in length and weighed around 180 kg (400 pounds).1
• Locomotion: It had long, powerful hind legs for running and short forelimbs with three sharp claws for grasping.1
• Diet: It was carnivorous, with a flexible lower jaw and large, inward-curving teeth adapted for holding prey.1
• Evolutionary Significance: Herrerasaurus lived just before dinosaurs became the dominant land animals. Its remains are crucial for understanding early dinosaur evolution, as it closely resembled the common ancestor of all dinosaurs and retained predatory features. While some traits, like its three-toed feet, are similar to theropod dinosaurs, it lacks certain distinguishing features like overlapping wrist bones.1

The first fragmentary remains were discovered in the early 1960s, but more complete skeletons found in Argentina in 1988 allowed for a clearer understanding of this ancient animal. Paleontologist Paul Sereno discovered one of the first well-preserved skeletons of Herrerasaurus ischigualastensis.12