Temporal range: Upper Cretaceous
A. calvoi Bonaparte, 1991 (type)
It was named by paleontologist Jose Bonaparte in 1991. It walked on two legs, had a long tail, and its leg structure suggests that it was a fast runner. It may have eaten insects. It was more primitive than other, better-known members of its family, such as Mononykus and Shuvuuia.
In popular culture [change]
Alvarezsaurus was featured in the Discovery Channel television series Dinosaur Planet, which speculated that it was a predator of young Saltasaurus, although these species did not exist at the same time, Alvarezsaurus being about 5 million years older than Saltasaurus.