Herrerasaurus

From Wikipedia, the free encyclopedia

Herrerasaurus
restoration of Herrerasaurus ischigualastensis
Conservation status
Extinct (fossil)
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Sauropsida Superorder: Dinosauria Order: Saurischia Suborder:  ?Theropoda Infraorder: Herrerasauria Family: Herrerasauridae Genus: Herrerasaurus Species: H. ischigualastensis
Binomial name
Herrerasaurus ischigualastensis Reig, 1963

Herrerasaurus was one of the earliest carnivorous dinosaurs. It lived in what is now Argentina, during the Late Triassic Period (Carnian stage).

Herrerasaurus was named after Victorio Herrera, the farmer who first noticed its fossils in outcrops near San Juan in 1959, although a complete skull was not found until 1988. The book The Dinosaur Hunters, by David Spalding, identifies Victorino (not Victorio) Herrera as a goatherd and states that Osvaldo Reig was the paleontologist who suggested the name. It has been brought into wider notice by Paul Sereno.

It is estimated that Herrerasaurus could reach up to 15 feet (5 meters) in length. It was a bipedal carnivore, which most likely fed on small and medium-sized animals. It had strong hind limbs with short thighs and rather long feet, which means that it was most likely a swift runner. Herrerasaurus was one of the first dinosaurs and was one of the first animals to embody the distinctive 'carnivorous dinosaur' (theropod-like) shape, but there is still discussion as to whether they were basal theropods, basal saurischians or evolved prior to the saurischian-ornithischian split.

Although Herrerasaurus shared the body shape of the large carnivorous dinosaurs, it lived at a time when dinosaurs were small and insignificant. It was the time of reptiles, not dinosaurs and a major turning point in the Earth's ecology. By the end of the Triassic Period, dinosaurs would rule the planet and the mammal-like reptiles would be nearly gone. At the same time, some of the first mammals began to evolve.

Herrerasaurus lived alongside another early dinosaur (about 230 million years ago), Eoraptor, as well as Saurosuchus, a giant land-living crocodylian, in the jungles of Late Triassic South America. Originally found in the Patagonia region of Argentina, one specimen can be found in the Chicago Field Museum of Natural History.

This dinosaur is an enigmatic creature, showing traits that are found in different groups of dinosaurs. It is also similar to much later Jurassic dinosaurs. Some fossils indicate that Herrerasaurus could grow up to 3 meters in length and 1 meter in height.

[edit] References

Dixon, Dougal. 'The Complete Book of Dinosaurs.' Hermes House, 2006.