Origin of the eoraptors
The first of the dinosaurs are believed to have walked on the surface of the earth about 230 million years ago and this period is referred to as the Triassic era. During this Triassic period, the earth comprised of a single landmass which was known as Pangaea and in this period huge monstrous animals treaded the earth of which one of the foremost were the dinosaurs. The dinosaurs lived for several millions of years and they multiplied and there were numerous varieties of dinosaurs that tread the surface of the earth.
However, it was during the late cretaceous period that a violent catastrophe resulted in the absolute extinction of the dinosaurs from the face of the earth. Today the dinosaurs are no more living but the modern birds contain several features which have led the researchers to denote that they are genus of the primitive dinosaurs. Certain features of the familiar reptiles like lizards and crocodiles are also similar to that of the dinosaurs. Since then dinosaurs have been a fascinating topic of study among children and adults and researchers and paleontologists are always on the look out for bringing forth newer facts regarding the dinosaurs from time to time.
In terms of structure and physical features the eoraptor is considered to be the predecessor of all dinosaur variants. However, there is certain dinosaur specimens recovered recently in Madagascar and these are considered to be older than the eoraptor.
According to the theories of evolution, the early dinosaurs evolved during the Triassic period and one of the most primitive of the dinosaur variants were known as the eoraptor. It is interesting to note that the very first specimens of the eoraptor was unearthed in the 1990s in the Ischigualasto Formation in Argentina and what proved to be quite advantageous for the paleontologists and the scientists was that in this excavation they were able to recover an entire skeleton of the eoraptor and it is upon an extensive study of this skeletal remains that the scientists have come to the conclusion that the eoraptor was one among the most primitive dinosaurs along with other theropods like herrerasaurus. In fact various recent evidences have proved that the eoraptor was even more ancient than the herrerasaurus and followed after a few kinds of prosauropods.
The eoraptor was a bipedal carnivorous theropod dinosaur and belonged to the saurischian group of dinosaurs. The saurischians refer to the lizard hipped dinosaurs and the eoraptor was considered to be one among them because of the structure of its hips. The term eoraptor is drawn from its Greek roots and means the ’dawn thief’. There have been several facts to suggest that the eoraptor was one of the earliest dinosaurs.
The major evidences in this case have been provided by the fact that the eoraptor lacked certain specialized features that are found to be fully developed in various other later species of carnivorous dinosaurs. For example the kinds of teeth it possessed and the structuring of the lower jaw were very unlike the well developed features of the later carnivores.
Taxonomy
The eoraptor was a theropod dinosaur which existed during the Triassic period and it is usually subdivided into a single major specie. This is known as the eoraptor lunensis and it means the ‘dawn plunderer from the valley of the moon’ according to its origins in the Greek dialect. The term ‘lunensis’ is derived from the Latin roots which mean ‘of the moon.’ The naming of this variety as eoraptor lunensis is based on the ancient river valley in South America from where its remains were unearthed.
The body of the eoraptor was light weight and not quite broad and it measured about 3 ft in length and weighed about 10 kgs. The hind legs were the ones used by the eoraptor in order to walk and these were long and thin.
Physical Features
The eoraptor was a carnivore i.e. a meat eater and it is believed to have displayed predatory characteristics. This is why the eoraptor is believed to have been a swift and fast runner. The forelimbs were much shorter compared to those of the hind limbs and according to popular perception they were not used for the purpose of walking.
The forelimbs on the other hand consisted of sharp claws or digits about three in number which aided the eoraptor in hunting down preys. There were a total of five digits and the remaining two were considered useless for hunting. The three sharper ones were longer digits while the two remaining were shorter ones. Unlike the fore limbs the legs consisted of only three digits which were contained pointed claws.
The eoraptors were extremely intelligent and swift moving and many consider it to be quite similar in terms of appearance to qualify as a miniature version of the tyrannosaurus rex. At the end of the long neck, was situated the skull of the eoraptor and the skull quite insignificant compared to the rest of the body was extremely strong and comprised of a set of hollow bones. The eyes were placed on the sides and the jaws were constituted by innumerable sets of serrated teeth which were of great help to the eoraptor.
Behavioral patterns and hunting
This is because the eoraptor was a meat eater and hence these jagged edges of the teeth enabled the eoraptor to capture the prey and tear its flesh. In this case, it was not only the sharp edged teeth but also the pointed claws that contributed immensely to aid the eoraptor in establishing its authority over its prey. The eoraptor was not only a meat eater but it is believed to have been a fierce hunter and hence the name ‘dawn plunderer’ is attributed to it.
While most paleontologists and scientists would refer to the eoraptor to be a carnivore, there are various evidences to suggest that this saurischian dinosaur was also a consumer of plant matter. For example the presence of five digits or fingers on the forelimb and certain kinds of herbivore teeth have fuelled this possibility. Therefore it is better to refer to the eoraptor as an omnivore. The eoraptors usually fed on smaller animals and there have been no proof of it displaying cannibalistic behavior like many of its counterparts.
The swift movement of its legs allowed the eoraptor to catch hold of its prey effectively before consuming it. there are also several scientists and researchers who are of the opinion that the eoraptor may have been a scavenger as well.
But it is absolutely true that the eoraptor had predatory characteristics.