Phalanx bone The proximal phalanges join with the metacarpals of the hand or metatarsals of the foot at the metacarpophalangeal joint or metatarsophalangeal joint. The intermediate phalanx is not only intermediate in location, but usually also in size. The thumb and large toe do not possess a middle phalanx. The distal phalanges are the bones at the tips of the fingers or toes. The proximal, intermediate, and distal phalanges articulate with one another through interphalangeal articulations. Each phalanx consists of a central part, called the "body", and two extremities. In the foot, the proximal phalanges have a body that is compressed from
Diandongosuchus The astragalus and calcaneum bones of the ankle fit together like a ball-and-socket, a feature that confirms "Diandongosuchus" as a pseudosuchian. Some of the phalanges or toe bones are missing in ZMNH M8770, but the metatarsals are present and have unique proportions among Triassic archosaurs in which the fourth is longer than the third. A phylogenetic analysis conducted by Li "et al." (2012) in the original description of "Diandongosuchus" showed that it was the most basal member of a clade called Poposauroidea, which includes mostly terrestrial pseudosuchians such as the bipedal "Poposaurus" and the sail-backed "Arizonasaurus". It was found to