Answer :
Final answer:
a. Apes are divided into lesser apes and great apes.
b. All primates have this but Apes don't have bilophodont molars.
c. All primates have molars, but apes possess distinctive Y-5 molars adapted to their omnivorous diet, unlike the bilophodont molars found in monkeys.
Explanation:
Apes are a group of primates that have evolved from the catarrhines in Africa approximately 25 million years ago. They do not possess a tail and are divided into two groups: the lesser apes, which comprise the family Hylobatidae, including gibbons and siamangs, and the great apes, which include the genera Pan (chimpanzees and bonobos), Gorilla (gorillas), Pongo (orangutans), and Homo (humans).
All primates have molars, but unlike cercopithecoid monkeys with bilophodont molars, apes have Y-5 molars, which feature five cusps separated by a "Y"-shaped groove pattern. This Y-5 molar pattern is more primitive and was present in the ancestors of hominoids. The structure and pattern of these molars might suggest diet variations and how different primates chew their food.
The shape and cusp pattern of molars usually inform about the dietary habits, as different patterns are adapted for processing different types of food. Apes' Y-5 molars are likely adapted to their omnivorous diets, allowing them to process various foods including fruits, leaves, and seeds.