Indochinese black langur

The Indochinese black langur, Trachypithecus ebenus, is a poorly known Old World monkey native to Laos and adjacent Vietnam. It was originally described as a subspecies of Trachypithecus auratus but was later found to belong to the Trachypithecus francoisi group, with some keeping it as a subspecies of François' langur, and in 2001 it was recommended that it be treated as a separate species. Except for its almost entirely black pelage it resembles the other members of that group. It and the related Hatinh langur appear to be parapatric, with signs of intergradation, and genetically the two are barely separable, which has led to the suggestion that it is a black morph of the Hatinh langur. A survey of 67 Hatinh langurs found high variation in the amount of white on the head. The IUCN formerly considered it data deficient and now includes it in the endangered Hatinh langur.