DIFFERENCES BETWEEN NEW WORLD MONKEYS AND OLD WORLD MONKEYS

Monkeys grow well in the subtropical and tropical regions of South and Central America, Asia and Africa where they are mostly dominated. "New world monkeys belong to order Platyrrhini they are limited to tropical environments and they are mostly herbivores. They feed on fruits, nuts and gums some also prey small insects. There are about 53 species of new world monkeys and they are divided into three families and sixteen genera these families include Callithricidae, Cebidae and Atelidae. The old world monkeys belong to the order Catarrhini which consists of two superfamilies"(1). The platyrrhini evolved from the ocean.

The new and old world monkeys look similar if you are observing them from a distance but if you take a close look you can see some unique and distinctive difference between them. These two monkeys can be easily differentiated looking at faces. "The new world monkeys have a flat face and their nostrils are far apart and open on the side. They have three molars which are very large but in most cases the last molar is smaller and in some monkeys they are not there. The ear of the new world monkey has a trampanic membrane connected to the external ear by a bony ring. They have different tails, but some species like howlers and spiders are composed of prehensile tails. The thumb orientation of their hands lies in the line with other digits while opposing the next digit in a scissor like grip. Some species like spider monkeys have lost their thumbs. Male species contribute a lot when it comes to infant care. The old world monkeys have a down facing nose with nostrils that are closer together and open down ward and sometimes forward. They have two premolars, premolar found in the mandible is sectorial meaning that it is specialised for sharpening the upper canine and their molars have sharply connected cusps. The tympanic membrane is connected to the external ear by the bony tube which is visible on the outside of the skull. Old world monkeys have tails all of them but they lack prehensive feature"(2). These tails are considered as the sitting pads as the monkeys sit on trees.

The thumbs are more like of modern people, they are rotated and more opposed. In some monkeys the thumbs are reduced or absent. The fingernails and toenails are present at all types of monkeys. The old world male monkeys do not have a close relationship with their infants.
They tolerate wide range of habitats, including rainforest, through savanna fringe or open savannah to semiarid regions. Many spend most of their day underground (2).

Reference

1. Wikipedia contributors. Monkeys [Internet]. Wikipedia, The Free Encyclopedia; 2006 May 16; 15:40 UTC [Cited 2006 May 15]. Available from:
http://en.wikipedia.org/wiki/Monkeys

2. Wikipedia contributors. Comparisons [internet] Wikipedia, The free encyclopedia 2006 May 11; 16:05 UTC [cited 2006 May 11]. Available from:
http://www.cabrillo.edu/~crsmith/monkeycomparisons.html

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