The Northern Muriqui or Woolly Spider Monkey is one of the world's most critically endangered primates. It is found in the Atlantic Forest region of the Brazilian states of Rio de Janeiro, Espírito Santo, Minas Gerais and Bahia. Muriquis are the largest species of New World monkeys.These Northern Muriqui, part of the largest known population, were filmed and photographed in the forests of the Caratinga Biological Station, an 890-ha private reserve in the state of Minas Gerais, Brazil.