Stephen Nash's titi as on the underside of the species' limbs. It is 28 inches long, although 17 inches is taken up by the titi's tail. Stephen Nash's titi Stephen Nash's titi ("Plecturocebus stephennashi"), also known as just Nash's titi or Stephen Nash's monkey, is a species of titi, a type of New World monkey, endemic to the eastern bank of the Purus River in Brazil. It was discovered by Marc van Roosmalen in 2001 when local fishermen brought specimens to his breeding center. It was described in 2002. It was named in honor of Stephen D. Nash, an illustrator for Conservation International,
Coimbra Filho's titi preferred habitat for Coimbra Filho's titi consists of densely wooded areas, preferring the dense understory and lower canopy. However, it is able to survive in damaged or fragmented forests, which currently comprise a large portion of its range. This is due to a tolerance to highly disturbed areas, as well as the ability to subsist in areas composed primarily of young or second growth forests. While other species in "Callicebus" are native to many areas of South America from Colombia to Brazil, Peru and north Paraguay, Coimbra Filho's titi is found only in a very small area in the states