DIFFERENCES BETWEEN NEW WORLD MONKEYS AND OLD WORLD MONKEYS

Monkeys constitute 90 percent of the 145 living species of the suborder anthropoidea. They are the most successful primates in populating the earth. Monkeys are more intelligent and their eyes are well developed as compared to the prosimians.

However there are two different infraorders of anthropoidea that have been evolving independed of each other for many years. These are the platyrrihini (new world monkeys) and the catarrhine (old world monkeys, apes and humans). Both monkeys eat leaves, fruits, nuts, gums and some small insects. Both the old world monkeys and the new world monkeys share the same kinds of teeth. They both have the same kinds of specialised mammalian teeth of which they are used to eat a wide variety of foods.

Although they share some of their characteristics, they can be easily distinguished looking at their nostrils, ear region, tails, hand, infant care, premolars and molars.
These two diverse groups of species can be distinguished from each other quite a number of characteristics the new world monkeys are almost exclusively arboreal and they are smaller than the old world monkeys have the capability of grasping branches of trees using tails but the old world monkeys do not have this capability.

Many old world monkeys have hairless callous pads, on their rumps which may be adaptations for long periods of sitting or sleeping on rough branches and rocks but the new world monkeys do not have it. The new world monkeys have relatively large molars of which are far apart and open to the side. The old world monkeys have the down facing nose; nostrils are closer together and open down ward.

The new world monkeys have relatively large molars of which the last molar is comparatively small or absent and three pre molars. In contrast the old world monkeys have two premolars and the molars have sharply connected cusps. The ear region of the new world monkeys is a tympanic membrane connected to external ear by a bony ring whereas to the old world monkeys the tympanic membrane connected to external ear by a bony tube.

The old world monkeys have tails but lack prehensibility feature. They have a sitting pads around the tail region which is a thickly calloused skin areas supports the animal while they sit in trees or while resting, but the new world monkeys have a tail with prehensile tails. The old world monkeys have thumbs that are rotated and more opposable which look like of humans. They have toe tails and finger nails are present on all digits.


In the old world monkeys, the males are less involved in caring for the infants where as the males of the new world monkeys are more involved. When coming to their habitat these two differ in a way that the old world monkeys tolerate a wider range of habitats, form rain forest through savannah fringe and semi arid regions and they also spend much of the day on the ground. The other distinguishing factor is that the new world monkeys have developed way of defending territory in the top branches of their forest canopies with localisation of which they use their specialized larynx and throat.

All monkeys irrespective of new world monkey or an old world monkey, they are both intelligent and they behave like humans.


Reference:

1. Anthropology 1, new world (America) and old world (Africa and Asia) monkey: A comparison, [internet] [cited 2006 May 11] Available form:
http://www.cabrillo.edu/~crsmith/monkeycomparisons.html

2. New world monkeys, [internet] [cited 2006 May 11] Available from:
http://anthro.palomar.edu/primate/prim-5.htm


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