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
Altun Ha is, is dated to about 600−650, which is at the beginning of the Late Classic period. The tomb is the seventh and earliest in B-4, which made the excavators designate this burial Tomb B-4/7. Tomb B-4/7 contained the skeleton of an adult male with many offerings. The body was fully extended dorsally with the skull facing south-southwest. The person had a height of 170–171 cm, with the recovered skeletal materials consisting of a fragment of the skull, the mandible, long bones, five teeth, two vertebrae, five carpal bones, the patellas, and miscellaneous metacarpals, metatarsals, and phalanges. The bulk of the