|Scientific name :||Eoraptor lunensis|
|Time period :||Late Triassic|
|Primary diet :||Carnivore|
|In the series|
|Fatalities caused :||four maybe five Probelesodon.|
|Appearances :||Evolution's Winners|
Physical Description Edit
Eoraptor had a slender body that grew to about 1 meter (3 ft) in length, with an estimated weight of about 10 kilograms (22 lb). It has a lightly built skull with a slightly enlarged externalnaris. Like the coelophysoids which would appear millions of years later, Eoraptor has a kink in its upper jaws, between the maxilla and the premaxilla. Sereno et al. (2013) observed that the lower jaw has a mid-mandibular joint. It ran digitigrade, and upright on its hind legs. The femur of the holotype specimen PVSJ 512 of Eoraptor is 152 mm, and the tibia is 157 mm, suggesting that it was a fast runner. Its forelimbs are only half the length of its hindlimbs, which would suggest that it was an obligate biped. All of its long bones have hollow shafts. Eoraptor had five digits on each 'hand', the three longest of which ended in large claws and were presumably used to handle prey. Scientists have surmised that the fourth and fifth digits were too tiny to be of any use in hunting. The ilium is supported by three sacral vertebrae, unlike that of the coeval Herrerasaurus which is supported by only two sacrals, a basal trait. Eoraptor had vertebral centra that are hollow, a feature present in some of its ancestors.
Bonaparte (1996) interpreted the relatively large orbital opening in the skull as a juvenile trait. Tykoski agreed (2005) and suggested that certain skull features of the type specimen suggested that it was young, specifically, the skull bones are not completely fused, relatively large orbits, and a short snout. Sereno et al. (1993), supported the notion that Eoraptor was an adult specimen based on the closure of sutures in the vertebral column, and the partial fusion of the scapulocoracoid.
During the Late Triassic Period, the Ischigualasto Formation was a volcanically active floodplain covered by forests, with a warm and humid climate, though subject to seasonal variations including strong rainfalls. Vegetation consisted of ferns, horsetails, and giant conifers, which formed highland forests along the banks of rivers. Herrerasaurus remains appear to have been the most common among the carnivores of the Ischigualasto Formation. Sereno (1993) noted that Eoraptor was found in "close association" with therapsids, rauisuchians like Saurosuchus, archosaurs and the dinosaurs Herrerasaurus and Pisanosaurus, all of whom lived in its paleoenvironment. Herbivores were represented by rhynchosaurs such as Hyperodapedon (a beaked reptile); aetosaurs (spiny armored reptiles); cynodonts like Probelesodon, kannemeyeriid dicynodonts (stocky, front-heavy beaked quadrupedal animals) such asIschigualastia; and traversodontids (somewhat similar in overall form to dicynodonts, but lacking beaks) such as Exaeretodon. These non-dinosaurian herbivores were much more abundant than early dinosaurs. Dinosaur fossils, including those of Eoraptor only represent approximately 6% of the total sample that has been recovered from the Ischigualasto Formation (Rogers et al., 1993), which suggests that dinosaurs were less numerous than other tetrapods.
Eoraptor was a small dinosaur and probably only hunted incects, small invertebrates, small vertebrates, early cynodonts such as Probelesodon and also some plants. It lived in South America at the Triassic period and was probably very vulnerable to other land predators.
In Dinosaur Revolution, one pecks at a Ischigualastia before a Saurosuchus attacks them and drives them away, while wounding the Ischigualastia. The females meet the males and they attempt to mate, but the Saurosuchus returns and injures a female, before getting back up with her mate and going into a cynodots underground home. There, a cynodont attacks the male, but the male kicks it out of the nest and into the Saurosuchus's mouth. Then they escape back into the outside world. After the male and female mate, they have eggs and one of the eggs hatch, but some cynodonts come and attack the eggs, but fail as the female kills one and proceeds to finish off the others. A baby Eoraptor gets out of the nest and into danger, falling down and is attacked by another cynodont, but the male throws it. The family goes to a dead Ischigualastia, but the Saurosuchus attacks, and tumbles down the rocky hill as the baby Eoraptor avoids it. It falls down and the parents watch as the Saurosuchus gets back up, but a trio of Ischigualastia appear and kill the Saurosuchus. The Eoraptor youngster survives and regroups with its parents.