Prosimians and Anthropoids Essay Example

groom (UM, 2006). In the case of Anthropoids, the cerebral cortex extends backward more and more to cover the large brain.

The skull becomes rounder, and spine and mouth are alarmingly close to each other underneath. Anthropoids have fused mandibles while prosimians do not have them. Anthropoids have nails whereas prosimians have claws. Anthropoids fill more niches than Prosimians- places which are drier, colder, sparser etc. In the case of fossil identification, the teeth are the key. In prosimians, the small molar crowns have spiky cusps and deep recessions (are "tuberculosectorial”). In higher primates the crowns are broader, more level, with shallower, blunter cusps (UM, 2006).

The earliest known anthropoidlike fossils were the ones that the Austrian collector Richard Markgraf found at Fayum in Egypt. They were studied in 1911 by Schlosser, and belonged supposedly, to the early Oligocene. He named them Parapithecus and Propliopithecus. Propliopithecus, has the catarrhine tooth count and is instantly recognizable as a hominoid (division of anthropoid). His teeth are of simple pattern and include a fairly short and light canine and unspecialized bicuspids or premolars, not skewed in the direction either of later apes or of strongly "bicuspid" man.

Parapithecus was still simpler in nature. His incisors, canines and premolars all shaded into one another so gradually that it has never been decided which was which. For a long time the dental formula was accepted as being 2-1-2-3, making Parapithecus the perfect emerging hominoid. But Schlosser himself thought that the formula was one incisor and three premolars, so that at best he would be a dubious hominoid and perhaps not even a primate at all. Parapithecus eventually proved to have teeth more like

a New World monkey's than an ape's (Cirulis et al, 1967).