The tufted gray langur (Semnopithecus priam), also known as Madras gray langur, and Coromandel sacred langur, is an Old World monkey, one of the species of langurs. This, like other gray langurs, is mainly a leaf-eating monkey. It is found in southeast India and Sri Lanka. It is one of three Semnopithecus species named after characters from The Iliad, S. hector and S. ajax being the others. In Sinhala it is known as හැලි වදුරා (Heli wandura).
There are two subspecies, Semnopithecus priam priam in India, and Semnopithecus priam thersites from Sri Lanka.
There are two theories about the evolution of these two subspecies. According to one theory, Semnopithecus priam arose from subspecies Semnopithecus vetulus philbricki. With the glacial fluctuations, and far apart of Indian subcontinent, pushed two taxa apart, but both retained key adaptation to folivory, and a ruminant-like stomach. Thereafter, S. priam invaded India, when there was a land bridge and there split off into two subspecies of S. priam.[4] In the other theory, Sri Lankan subspecies S. priam thersites evolved from the endemic S. vetulus, whereas, Indian subspecies S. priam priam evolved from the S. johnii, which results the genetic variations between two S. priam subspecies.
Madras or Tufted Gray Langur (Semnopithecus priam priam) - Chinnar National Park, Tamil Nadu
