Herrerasaurus

What it was like

Herrerasaurus was one of the earliest known dinosaurs, a bipedal meat eater that grew to about 4.5 meters (15 feet) long. It had a long skull with sharp, curved teeth and strong hind legs built for fast movement.

Its hands had sharp claws for grabbing prey, and it probably hunted small reptiles and other early animals of its time. For years, scientists debated exactly where Herrerasaurus belonged on the family tree, and some early studies were not even sure it was a true dinosaur.

Its world

Herrerasaurus lived from about 237 to 227 million years ago, during the Late Triassic, in what is now Argentina. All known fossils come from the Ischigualasto Formation.

It shared its world with other early dinosaurs, including Eoraptor, Panphagia, and Eodromaeus, at a time when dinosaurs were still a small part of a world dominated by other kinds of reptiles.

How it was found

Reig named Herrerasaurus in 1963, based on fossils found in Argentina. Around 11 finds are now known, including a nearly complete skeleton that helped settle much of the early debate about its classification. Its closest relatives include Staurikosaurus and Sanjuansaurus, other early saurischian dinosaurs from South America.