The northern muriqui (Brachyteles hypoxanthus) is an endangered muriqui (woolly spider monkey) species endemic to Brazil. It is unusual among primates in that it shows egaliterian social relationships. 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. The northern muriqui can grow up to 4.3 ft tall. It feeds mainly on leaves and twigs, but will also eat fruit. It often hangs upside-down by its prehensile tail while eating.