Of the many dinosaurs discovered so far, Eoraptor is the most primitive. In 1993, Eoraptor was discovered in the Ischigualasto Basin, an extremely barren and desolate area in northwestern Argentina, South America, which belongs to the Triassic strata.
The discovery of Eoraptor was purely accidental. At the time, Sereno, Ruba, and their students were conducting a scientific expedition in the Valley of the Moon when they discovered a nearly complete skull fossil in a pile of abandoned rocks by the roadside. The excavation team seized the opportunity and repeatedly "sweeped" the area around the pile of rocks. Before long, a very complete dinosaur skeleton appeared before them. What was even more surprising was that they had never seen this species before.
They named it Eoraptor. Compared to Herrerasaurus, Eoraptor was like a cat compared to a tiger, as it was only about 90 centimeters long, less than 1 meter, and weighed only 5-7 kilograms. Interestingly, on Eoraptor's upper and lower jaws, the hind teeth resembled grooved steak knives, similar to other carnivorous dinosaurs; however, the front teeth were leaf-shaped, similar to other herbivorous dinosaurs. This feature suggests that Eoraptor likely ate both plants and meat.
The serrated teeth of Eoraptor undoubtedly identify it as a carnivorous dinosaur, and it possessed hands adept at catching prey. From the fossilized forelimbs of Eoraptor, we can infer that it was capable of capturing and killing prey of similar size. While we cannot precisely reconstruct the dinosaur's attack behavior and hunting process, its lithe and agile physique makes it easy to imagine that Eoraptor was capable of rapid hunts, and its diet certainly wasn't limited to small reptiles; it might even have included the earliest mammals—our ancestors…
Some characteristics of Eoraptor prove that it was one of the earliest dinosaurs to appear on Earth. For example, it had five "fingers," while the number of "fingers" of later carnivorous dinosaurs tended to decrease, with large carnivorous dinosaurs like Tyrannosaurus Rex having only two "fingers." Furthermore, Eoraptor had only three vertebrae supporting its small pelvic girdle, while later dinosaurs, as they grew larger, increased the number of vertebrae supporting their pelvic girdle.
The appearance of Eoraptor and Herrerasaurus in the Late Triassic represents the dawn of the dinosaur era.
Chinese name: Eurasian raptor
Latin name: Eoraptor
Age of existence: Late Triassic
Fossil origin: Argentina
Physical characteristics: Approximately 1 meter in length
Diet: Carnivorous
Type: Theropod
Meaning: Thief of Dawn
