The Rondon's marmoset (Mico rondoni), also known as the Rondônia marmoset,[1] is a small species of monkey from the family Callitrichidae found in the south-western Amazon in Brazil. It is endemic to the state of Rondônia, and its range bordered by the Rio Mamoré, Rio Madeira, Rio Ji-Paraná, Serra dos Pacaás Novos[2] and possibly Bolivia.