Which primate group is characterized by being arboreal and having tails?

The primate group characterized by being arboreal and having tails is indeed Platyrrhines, also known as New World monkeys. This group primarily inhabits the tropical forests of Central and South America, where they have adapted to life in the trees. Platyrrhines, which include species such as capuchins and spider monkeys, are notable for their prehensile tails, which function almost like an extra limb to help them navigate the arboreal environment. This adaptation is particularly important for their survival, as it allows them to grasp branches while foraging for food or escaping predators.

In contrast, while Old World monkeys (Catarrhines) can also live in arboreal environments, they are not exclusively arboreal like Platyrrhines and often have lesser adaptations for climbing. Additionally, although Tarsiiformes exhibit arboreal traits, they belong to a different suborder within Primates and have distinct features such as large eyes adapted for nocturnal living. Understanding these distinctions is vital for recognizing the unique ecological roles that these primate groups play in their environments.