spider and howler monkeys, and Old World monkeys like languars and baboons. Apes are somewhat similar to monkeys, but have no tail. As formulated by most biologists, they include gorillas, gibbons, chimps and humans. | spider and howler monkeys, and Old World monkeys like languars and baboons. Apes are somewhat similar to monkeys, but have no tail. As formulated by most biologists, they include gorillas, gibbons, chimps and humans. |