Herrerasaurus was bipedal and carnivorous. It would have been one of the very first dinosaurs ever to walk the planet.
Herrerasaurus fossils have been found in the Ischigualasto Formation of north-western Argentina. Today this landscape is known as the Valley of the Moon because of its eerie, moon-like geology. Here, palaeontologists have also found Eoraptor, another early dinosaur. The Ischigualasto landscape was a floodplain dominated by rivers and studded with volcanic activity 230 million years ago. Today, it is an arid, barren landscape.
The lower jaw was lined with large, inwardly curving teeth so that Herrerasaurus could hold its prey more efficiently.
Herrerasaurus was first discovered in 1958 by Victorino Herrera, a local Andean farmer, after whom the animal is named. That skeleton was incomplete, but the discovery of a complete skull in 1988 by palaeontologist Paul Sereno provided enough information to make a complete reconstruction. Herrerasaurus is important because it shows palaeontologists what dinosaurs were like just after or at the time they first evolved.
Height: 1m (3.28ft)
Length: 4m (13.12ft)
Weight: 210.01kg (463lbs)
Top speed: 40kph (24.85mph)
Vision: As a predator, Herrerasaurus would have had binocular vision so that it could judge distances and time to attack.
Skin: There is a possibility that Herrerasaurus sported simple feathers, because so many other theropods did.
Brain: Herrerasaurus had a simple, tubular brain, which would have been at the other end of the spectrum from the enlarged and complex brain of the birds. Herrerasaurus was no bird brain – it was much dumber!
Prey: Herrerasaurus' forelimbs were equipped with three large, recurved claws for grasping and raking. It even had a semi-opposable thumb to help capture prey. It fed on small and medium-sized herbivores such as Pisanosaurus, rhyncosaurs and synapsids.
Bite: Herrerasaurus had a dual-hinged jaw so that it could hold prey more tightly. Once a victim had been caught, there would have been no escape.