Mesopropithecus is an extinct genus of small to medium-sized lemur, or strepsirrhine primate, from Madagascar that includes three species, M. dolichobrachion, M. globiceps, and M. pithecoides. Together with Palaeopropithecus, Archaeoindris, and Babakotia, it is part of the sloth lemur family (Palaeopropithecidae). Once thought to be an indriid because its skull is similar to that of living sifakas, a recently discovered postcranial skeleton shows Mesopropithecus had longer forelimbs than hindlimbs—a distinctive trait shared by sloth lemurs but not by indriids. However, as it had the shortest forelimbs of all sloth lemurs, it is thought that Mesopropithecus was more quadrupedal and did not use suspension as much as the other sloth lemurs.
They are known only from subfossil remains and died out after the arrival of humans on the island, probably due to hunting pressure and habitat destruction. Mesopropithecus was one of the smallest of the extinct subfossil lemurs, but was still slightly larger than the largest living lemurs. Although rare, the three species were widely distributed across the island yet allopatric to each other, with M. dolichobrachion in the north, M. pithecoides in the south and west, and M. globiceps in the center of the island. All three species were primarily a leaf-eaters. (Read more...)