Eras of Life
 Dinosaur Evolution
 Feathered Dinosaurs




  Other Tyrannosaurs

New Discovery

  Guanlong Wucaii


   Hunter v Scavenger
   Family Life
   Growth Rate
 Weird Dinosaurs
 Prehistoric Sea Monsters



Eoraptor lunensis (Paul Sereno, 1933)

Name Means: "Dawn Thief" Length: 3 feet (1 m)
Pronounced: EE-o-rap-tor Weight: 20 pounds (9 kilos)
When it lived: Triassic - 228 million years ago    
Where found: Northwest Argentina, Madagascar    


    Eoraptor is one of the earliest known dinosaurs.  It was one one of the very first to ever walk on Earth. Although it was small, it was a fierce predator. Its speed and intelligence destined it to become the ancestor of many evolved species and the dinosaurs becoming the dominant land creatures.
    Eoraptor had the characteristics of later dinosaurs - serrated teeth, grasping hands (although there is some speculation that it occasionally walked using all four limbs), light hollow bones and a strong, light skull. Although it lived at the same time as the larger Herrerasaurus (which may have eaten Eoraptor), it has some significant differences. Some of its teeth were shaped differently and the bones in its hands were more primitive. Later dinosaurs tended to lose fingers, and by the time T. rex came onto the scene, it had only two fingers. Eoraptor had five. Even Herrerasaurus, which had five fingers, had a less useful fifth finger.


     A Eoraptor skull was discovered in a single rock by Ricardo Martinez in 1991 in Argentina, South America, in the Ischigualasto Basin. This area was a river valley during the late Triassic period but is a dry, eroding desert badlands today. Eoraptor was found in the same rock formation that yielded Herrerasaurus, another very early theropod.
   The Argentina Natural History Museum sent a team to investigate: Paul Sereno, Fernando Novas and others. They sound found an almost complete skeleton and have since discovered two others.  This creature has greatly increased scientists' knowledge of how dinosaurs developed and evolved. There are so few dinosaurs known from this time period that finding a complete skeleton of such an early member of the dinosaur family is a big help in expanding our knowledge of the early dinosaurs.
    Eoraptor was named by paleontologists P. Sereno, Forster, Rogers, and Monetta in 1993.


Poster is available at

Edugraphics.Net | Feenixx Publishing |