Question

What are the major differences between Platyrrhini and Catarrhini?

Answer 1

Platyrrhini and Catarrhini New World monkeys differ from Old World monkeys in a number of traits, some of which are as follows:

1. New World monkeys have flat noses with two nostrils separated by broad fleshy nasal septum. Nostrils of Old World monkeys project and point downward, and are separated by a narrow nasal septum.
2. Tails of New World monkeys are prehensile, while that of Old World monkeys are not prehensile. In some of the latter group tails are reduced or often absent.
3. Ischial callosities are absent in New World monkeys, but present in Old World Monkeys.
4. Cheek pouches are absent in New World monkeys and present in Old World Monkeys.

5. New World monkeys have arched nails, while Old

World monkeys have flat nails.

6. Thumbs and great toes of New World monkeys are slightly opposable, whereas those of Old World monkeys are capable of independent movement and completely opposable.
7. Old World monkeys have simple stomach. Among Old World monkeys in some it is simple and in others it is sacculated (divided into a series of sacs).
8. Kidneys of Old World monkeys have four or five pyramids and those of Old World Monkeys have a single pyramid.

9. Dental formula of Old World monkeys is 2.1.3.3, while that of Old World monkeys is 2.1.2.3.

10. Palates of Old World monkeys are short, while that of Old World monkeys are relatively long.

11. Tympenic bulla is absent in Old World monkeys. It is large and inflated in New World monkeys.
12. In Old World monkeys tympanic annulus is elongated and it forms tubular external auditary meatus. In Old World monkeys tympanic ring is absent.

13. In New World monkeys basicranial axis is long. It is relatively short in Old World monkeys.

14. In Old World monkeys premaxilla extends upward to nasal openings and often touches frontal bones. In New World monkeys it slightly overlaps the lower mar

gin of nasal bones.

15. In Old World monkeys fronto-temporal articulation is at pterion, while in New World monkeys it is jugo parital articulation at pterion.

16. In Old World monkeys bregma is placed relatively far forward than that in New World monkeys.

17. In Old World monkeys fronto-maxillary articulation is seen on the medial wall of orbit, while in Old World monkeys it is lacrymo-ethmoidal articulation.

Platyrrhini:

These are a division (Platyrrhina) of arboreal New World monkeys characterized by a broad nasal septum, usually 36 teeth, and often a prehensile tail and also having a short broad nose.

Catarrhini:

These are a division (Catarrhina) of primates comprising the Old World monkeys, higher apes, and hominids that have the nostrils close together and directed downward, 32 teeth, and the tail when present never prehensile.