Atelidae is a family of New World monkeys that are primarily found in Central and South America. These primates are known for their prehensile tails, which can grasp and hold objects much like an arm or a hand. Several synonyms are used to refer to the Atelidae family such as spider monkeys, woolly monkeys, and howler monkeys. The spider monkey is perhaps the most well-known of these primates, being a slender, agile species that gets its name from its long, thin limbs and tail. Woolly monkeys are known for their thick, dense fur, which keeps them warm and protected in the dense forest environments where they live. Howler monkeys get their name from their loud, distinctive vocalizations, which can be heard over great distances in the forest canopy.