Dorsal interossei of the foot Dorsal interossei of the foot In human anatomy, the dorsal interossei of the foot are four muscles situated between the metatarsal bones. The four interossei muscles are bipenniform muscles each originating by two heads from the proximal half of the sides of adjacent metatarsal bones. The two heads of each muscle form a central tendon which passes forwards deep to the deep transverse metatarsal ligament. The tendons are inserted on the bases of the second, third, and fourth proximal phalanges and into the aponeurosis of the tendons of the extensor digitorum longus without attaching to the extensor hoods of the
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