In 2010, Colin Groves and Myron Shekelle suggested splitting the genus "Tarsius" into three genera, the Philippine tarsiers (genus "Carlito"), the western tarsiers (genus "Cephalopachus"), and the eastern tarsiers (genus "Tarsius"). This was based on differences in dentition, eye size, limb and hand length, tail tufts, tail sitting pads, the number of mammae, chromosome count, socioecology, vocalizations, and distribution. The senior taxon of the species, "T. tarsier" was restricted to the population of a Selayar island, which then required the resurrection of the defunct taxon "T. fuscus".