What is "alvarezsauridae"

Alvarezsauridae was a group of small, long-legged dinosaurs. Although originally thought to represent the earliest known flightless birds, a consensus of recent work suggests that they evolved from an early branch of maniraptoran theropods. Alvarezsaurids were highly specialized. They had tiny but stout forelimbs, with compact, bird-like hands. Their skeletons suggest that they had massive breast and arm muscles, possibly adapted for digging or tearing. They had long, tube-shaped snouts filled with tiny teeth. They may have been adapted to prey on colonial insects such as termites.

Alvarezsaurus, the namesake member of the group, was named for the historian Gregorio Álvarez, not the more familiar physicist Luis Alvarez, who proposed that the Cretaceous–Paleogene extinction event was caused by an impact event.