Shuvuuia
Shuvuuia (derived from the Mongolian word for "bird," шувуу) was an unusual small feathered theropods from Late Cretaceous Mongolia. The most remarkable feature of its family, Alvarezsauridae, is their greatly reduced forelimbs, which ended in a single short but powerful claw. Shuvuuia and its brethren may have used these strange arms for digging.