Final answer:
New World monkeys are known for their prehensile tails used for arboreal locomotion, such as grasping and moving among tree branches, a key feature that distinguishes them from Old World monkeys.
Step-by-step explanation:
New World monkeys, also known as Platyrrhini, are distinct in their form of locomotion due to their prehensile tails, which they use for grasping and moving among the tree branches in the arboreal habitats where they live. These tails function as an 'extra limb' for additional support, which is a characteristic feature of these arboreal animals. Notably, this trait is absent in their Old World counterparts, known as Catarrhini, which include both arboreal and ground-dwelling species. These arboreal monkeys, such as spider monkeys and tamarins, exhibit a variety of adaptations for their tree-dwelling lifestyle, including a body that is semi-erect or erect, allowing them to move in several ways such as brachiation, where they swing from branch to branch. The prehensile tail is a key adaptation for this type of locomotion and is useful for climbing and maintaining balance in the trees.