Titi to the great diversity found across titi monkey species, a new genus-level taxonomy was recently proposed that recognises three genera within the subfamily Callicebinae; "Cheracebus" Byrne et al. (2016) for the species of the "torquatus" group (Widow titis); "Callicebus" Thomas, 1903, for species of the Atlantic Forest "personatus" group; and "Plecturocebus" Byrne et al. (2016) for the Amazonian and Chaco titis of the "moloch" and "donacophilus" groups. Titi The titis, or titi monkeys, are the New World monkeys of the subfamily Callicebinae, which contains three extant genera, "Cheracebus", "Callicebus", and "Plecturocebus." This subfamily also contains the extinct genera "Xenothrix, Antillothrix",
Collared titi is found west of the Río Purús to the Yavarí River. The collared titi is seen most frequently in well-developed, tall forest with a closed canopy, usually over terra firme, but not exclusively so. The species also enters extensive várzea forest, especially if the forest is tall and well-developed. Such várzea forest contrasts with the habitat needs of the coppery titi, which also uses várzea forest and more commonly so. But the coppery titi survives in low, vine-covered, "poor" forest where the collared titi is rarely found. It is also known from some gallery forest, north of the Vichada River,