The primates that are strictly arboreal and have a dental formula of 2.1.3.3 with post-orbital closure are classified as Strepsirhini. b. Hominids c. Catarrhini d. Platyrrhini e. Homininae
The Correct Answer and Explanation is:
The correct answer is d. Platyrrhini.
Here’s the explanation:
Primates are classified into two major suborders: Strepsirrhini and Haplorhini. The Haplorhini suborder is further divided into two infraorders: Platyrrhini (New World monkeys) and Catarrhini (Old World monkeys and apes).
- Platyrrhini (New World monkeys) include species that are typically arboreal (living in trees). These primates are characterized by having a dental formula of 2.1.3.3, meaning they have 2 incisors, 1 canine, 3 premolars, and 3 molars on each side of the upper and lower jaws. They are also noted for having a post-orbital closure, which means their eye sockets are fully enclosed by bone, providing better protection for their eyes. New World monkeys often have prehensile tails, which are capable of grasping and are adapted to their arboreal lifestyle.
- Catarrhini (Old World monkeys and apes) are characterized by a dental formula of 2.1.2.3, meaning they have 2 incisors, 1 canine, 2 premolars, and 3 molars on each side of their upper and lower jaws. Catarrhines also have post-orbital closure, but they are more commonly ground-dwelling than their New World counterparts.
- Strepsirrhini (which includes lemurs and lorises) is a separate suborder of primates. While they are typically arboreal, they have a different dental formula (usually 2.1.3.3 or 2.1.3.2) and a less complete post-orbital closure compared to Platyrrhini.
Thus, the correct classification for a strictly arboreal primate with a dental formula of 2.1.3.3 and post-orbital closure is Platyrrhini.
