Avisauridae leg formed by fused metatarsals (the bones which comprise the foot in humans). As a result, members of this family are distinguished from other enantiornitheans exclusively by features of the tarsometatarsal and pedal phalanges (toe bones). Unlike in some prehistoric birds, avisaurid tarsometatarsals were not completely fused, with the distal (outer) parts of the metatarsals being separate from each other. The proximal (near) half of metatarsal III (the long bone in the middle of the tarsometatarsus) is convex from the front. The inside edge of this bone's trochlea (toe joint) has a bony tab which points downward, known as a
Vancleavea parts of the hand. The second metacarpal is longer, and the third and fourth are tied for the longest bones of the hand. Unguals (claws) have not been found, and the rounded ends of certain phalanges indicates that "Vancleavea" likely did not possess them. As with other reptiles, each hip of "Vancleavea" is formed by three plate-like bones: the illium (above the hip socket), the pubis (in front of the hip socket), and the ischium (behind the hip socket). The illium of "Vancleavea" is particularly unusual. Most archosauriforms have illia which are somewhat low, directed from front to back (anteroposteriorly).