James Napoli, a vertebrate paleontologist and evolutionary biologist, found theropod dinosaurs had the pisiform, a small carpal bone that — while found in all limbed vertebrates — has a unique positioning in birds and plays a critical role in flight.
Identification of a carpal bone in the wrist of dinosaurs may alter scientists' view of the evolution of flight This is an illustration of an oviraptorid dinosaur called Citipati ... another carpal bone.