What is the difference between a cat and a platyrrhine?
The tarsiers are not the only living species of the Haplorrhini.The majority of them are monkeys.Humans and apes are the last two species.The anthropoids are the most successful primate in the world.They are larger and more intelligent than the prosimians.
For at least 30,000,000 years, there have been two distinct Parvorders of animals.The Catarrhini is for Old World monkeys, apes and humans.The two groups of species can be distinguished by their noses and the number of different types of teeth.
The platyrrhine nose is relatively flat with sideways nostrils separated by a wide septum.The catarrhine nose has more downward projecting nostrils than the other way around.If you look at your face in a mirror, you will see a catarrhine nose.
The Celebes black macaque and the emperor tamarin are both New World monkeys.
All primate teeth are adapted to eating a wide variety of foods.There are 2 incisors, 1 canine, and varying numbers of premolars and molars in the front of the mouth.The incisors are used to cut food.The pointed canines are used for piercing and tearing.The premolars and molars are used to grind and smash food.There are 3 premolars and 2 or 3 molars in platyrrhine.This results in a dental formula.All of the catarrhines have 2 premolars and 3 molars, making a dental formula of 2.1.2.3.The Chimpanzees shown below have a catarrhine dental formula.
Humans, apes, and monkeys all share the same dental formula.This sets us apart from New World monkeys and prosimians, but it also shows the evolution of the Old World anthropoid species.The general mammal dental formula is 3.1.4.
Most of the New World monkeys are smaller than the Old World ones.There are monkeys and apes in the Old World.If you see a group of monkeys walking around in a grassland environment, you can be certain that they are from the Old World.