Skeletal reconstruction of Eoraptor lunensis in Brussels
- Argentina ( Ischigualasto Formation )
- Eoraptor lunensis
Eoraptor ( "Raiders of the Dawn " ) is a genus very original dinosaur from the early Late Triassic ( Carnium ) of South America.
Its fossils were discovered in 1991 by an American- Argentine research group in the rocks of the Ischigualasto Formation in Argentina. He is one of the oldest known dinosaur, what its name alludes, and therefore for understanding the early evolution of these creatures of meaning. The only known species is Eoraptor lunensis. The Style epithet refers to the place where the first skeleton in the " Valle de la Luna" ( Moon Valley ) in the nature reserve Ischigualasto.
Eoraptor was no more than a meter and a man would have passed to the knee. His skull was only 12 inches long. His jaw was set with teeth that were suitable for crushing animal and vegetable food.
From its fossils, the scientists were able to gain much information about the early evolution of dinosaurs. In many ways it resembled more primitive, bipedal reptiles such Lagosuchus, but the altered structure of the legs and the nature of their connection with the pelvis clearly show that he was already a dinosaur.
Even if it is ensured that Eoraptor was a dinosaur, but the classification in the existing system is problematic because Eoraptor is the origin of dinosaurs near, as its diversification into the various major groups only began. So he resembled in his physique later theropods and has claws and bones of carnivores on. But in his jaw sat next to teeth with sawn edges, as they are characteristic of carnivorous theropods, including those that were similar to those of prosauropods, feeding on plants. Furthermore, there was still the Eoraptor Intramandibulargelenk in the lower jaw ( mandible ), which served in later theropods to be able to hold larger prey better. Thanks to the discovery of Eoraptor is well established that the dinosaurs evolved from small, bipedal reptiles. Its location in Argentina, in which many other very old dinosaurs have been found, is an indication that the origin of dinosaurs in South America could be.
The systematic classification within the dinosaurs is controversial. Although Eoraptor was traditionally kept for an original theropods (eg, Sereno and colleagues, 1993; Currie, 1995), several other studies suggest that it must be classified outside of theropods as the original Saurischia. Martinez and colleagues ( 2011), however, come to the conclusion that it was in Eoraptor an original representative of Sauropodomorpha ( Sauropodenverwandten ).