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The Eoraptor is one of the earliest identified dinosaurs that lie at the root of the Saurischian (“lizard-hipped” dinosaur group) family tree. These were very small, light-weight reptiles (probably the size of a dog like ‘beagle’) that walked the earth during the Late Triassic Period, with the first specimen being discovered only in 1991.


Scientific Classification

Kingdom Animalia
Phylum Chordata
Clade Tetrapodomorpha
Clade Dinosauria
Suborder Theropoda
Genus †Eoraptor
Species †E. lunensis

Quick Facts

Pronunciation EE-oh-RAP-tor
Geological Period Approximately 231 to 228 million years ago
Height (Size) About 3 feet
Length 100 cm
Weight 25 pounds (maximum)
Average Lifespan Up to 90 years
Location/Distribution Western Gondwana (presently northwestern Argentina)
Climate/Environment & Habitat Seasonally well-watered forests with a dense concentration of giant coniferous trees
Diet Probably omnivorous
Sound/Calls Not known
Birth Type (Reproduction) Oviparous (laying eggs)
Locomotion Bipedal (rarely walked on all four legs)
Predators/Enemies Larger dinosaurs like the Herrerasaurus

History and Discovery of the Skeleton

It was in 1991 that the fossil of the Eoraptor was excavated for the first time by eminent paleontologist Ricardo Martinez in a joint venture by Argentina and USA. The site was in Argentina’s Ischigualasto Basin wherefrom skeletal remains of a nearly complete new dinosaur were unearthed.

Presently, this region is a barren area; however, scientists think that it was a river valley during the late Triassic Era. Interestingly, it was this very region from where the first fossils of the Herrerasaurus were also found.

Later, in 1993, paleontologists Paul Sereno and Fernando Novas named it the ‘Eoraptor’. This specimen was one of the oldest lines of dinosaurs to have ever been discovered, which is thought to be a common ancestor of the dinosaurs in general.

While the research about this animal is on, the classification of this reptile is still difficult to place. Some scientists opine that they are even older than the primitive Herrerasaurus. It is, however, accepted in general by the world’s paleontologists that these lizards belonged to the Theropod group that evolved after the latter split from the Sauropod group of dinosaurs.

Physical Description

By evolution, the eoraptors were one of the most primitive theropods. Their body and head (skull) were small, while they were mostly bipedal, seldom using all four arms.

Each of its hands bore five digits, out of which, three were clawed, while the remaining two probably had no use. These two fingers were rather small, perhaps adapted to keep its balance while walking on all fours.

The two forelimbs were thin and short, almost half the size of the hindquarters. Their dentition show both herbivorous and carnivorous sets of teeth, which made the biologists presume that they might have been omnivores.


Eoraptors are thought to be omnivores; however, they certainly consumed almost all small animals living around it. It was a swift and speedy runner that would usually win catching its prey. Eoraptors used their razor-sharp teeth and pointed claws to tear the prey apart.


These lizards would prey upon smaller game including the Panphagia and the Pisanosaurus, and also consumed some easily digestible plant materials. They would also scavenge larger animals.

Interesting Facts

  • Some paleontologists still believe that only juvenile specimens of the eoraptor have been found so far.
  • The ancient creature appeared in the American nature documentary Dinosaur Revolution that utilizes computer-generated imagery. In this telecast, it has been shown saving a female from a Saurosuchus and later had a child.
  • The eoraptor has also been featured in several apps and games including the Dinosaur Train app and the game named Fossil Fighters: Champions.
  • The meaning of the name ‘Eoraptor’ in Greek is ‘Dawn Plunderer’, which is a reference to its presumed carnivorous nature and its grasping claws.

Published on November 5th 2018 by under Reptiles.
Article was last reviewed on 16th September 2019.

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