Troodon: The Smallest Dromaeosaurid

Trierarchuncus is a miniature dromaeosaurid dinosaur from Late Cretaceous North America, measuring less than 1 meters in length. One of the smallest known dromaeosaurids, it was roughly turkey-sized. Fossils discovered in Montana's Hell Creek Formation indicate it lived alongside Tyrannosaurus rex and Triceratops. Despite its small size, Trierarchuncus retained typical dromaeosaurid features, including the sickle-shaped claw on its hind foot. Covered entirely in feathers, it provides key evidence for the evolutionary transition from dinosaurs to birds. Its discovery shows that even at the end of the Cretaceous, small theropod dinosaurs remained highly diverse.