Final answer:
New World monkeys of the Ceboidea group are characterized by their prehensile tails, opposable thumbs, stereoscopic vision, and habitats in Central and South America, including diverse ecosystems such as rainforests and urban areas.
Step-by-step explanation:
The defining characteristics of monkeys belonging to the Ceboidea group, also known as New World monkeys, include specific adaptations of their hands, tails, vision, and habitat. These primates have prehensile tails that are capable of grasping, acting as an extra limb for arboreal locomotion. Their hands exhibit opposable thumbs, which provide significant manual dexterity, allowing them to grip and manipulate objects effectively. Concerning their vision, New World monkeys have stereoscopic vision which enhances depth perception, important for navigating through the treetops where they primarily reside.
New World monkeys are predominantly found in Central and South America, inhabiting diverse environments ranging from tropical rainforests to cloud forests. Some species have even adapted to urban areas, demonstrating remarkable ecological versatility. Notably, a few species like the proboscis monkey and De Brazza's monkey have evolved partially webbed hands for swimming, showing specialized adaptation for an aquatic or swamp habitat.