Balabac Chevrotain

The Philippine mouse-deer (Tragulus nigricans), also known as the Balabac chevrotain or pilandok (in Filipino), is a small, nocturnal ruminant, which is endemic to Balabac and nearby smaller islands (Bugsuk and Ramos) southwest of Palawan in the Philippines. The genus Tragulus means 'little goat' and the Philippine mouse-deer has been named so due to the horizontal pupils of the eyes. This position of the pupil allows for an increase in peripheral depth perception. It has traditionally been considered a subspecies of the greater mouse-deer (T. napu). In 2004, though, T. nigricans was separated from T. napu as its own species due to differences in skull morphology (skull measurements). Contrary to its common name, the Philippine mouse-deer does not belong to the true deer family (Cervidae); it is a member of the chevrotain family, a grouping of some of the world's smallest hoofed mammals.

Excerpt from the Wikipedia article Philippine mouse-deer, by its authors, under the CC BY-SA 4.0 licence.