Lesson's saddle-back tamarin (Leontocebus fuscus) is a species of saddle-back tamarin, a type of small monkey from South America. Lesson's saddle-back tamarin was formerly considered to be a subspecies of the brown-mantled tamarin, L. fuscicollis.[1] [2] Genetic analysis showed it to be more closely related to the black-mantled tamarin than to the brown-mantled tamarin.[2] Its type locality is in Colombia, in Plaines de Mocoa, Putumayo, between the Rio Putumayo and Rio Caqueta.[1] It also lives in Brazil.[2]
Lesson's saddle-back tamarin has a head and body length of between 212mm and 234mm.[2] Males have tails between 296mm and 383mm long, and females have tales between 337mm and 362mm long.[2] It weighs between 350g and 400g.[2]
It sometimes associates with Goeldi's marmoset.[2] The IUCN rates it as least concern from a conservation standpoint.