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4.6.1. Primates

The primates

The primates are a group of placental mammals to which belong humans and other closely related species. Primates are characterized by having five fingers, and similar teeth, among other common characteristics.

The order Primates are divided into two suborders:

Of the 150 known genera, two-thirds are already extinct.

We will do a quick review of the first primates to see how their evolution has been until reaching the Homo sapiens sapiens today.

Purgatorius

The Purgatorius is considered the first protoprimate (ancestor of the primates), arisen from small arboreal mammals that survived the extinction produced at the end of the Mesozoic. Therefore, it would be the only primate that lived with the dinosaurs. It was able to survive the impact of the meteorite that ended the dominance of the reptiles on Earth, hibernating in burrows, and thanks to that we exist and are here with Biology and Geology from 4th of ESO.

Some paleontologists doubt that it is really a primate because it has a somewhat different dentition from other primates.

It was a small animal, similar to a rat, about 15 cm and one kilo in weight. They were arboreal and omnivores.

Purgatorius es considerado como el primer primate

By Nobu Tamura (Own work) [GFDL or CC BY 3.0], via Wikimedia Commons

In the middle of the Cenozoic, the climate changed in Africa, becoming more arid and decreasing the number of trees, changing the forests for the current savannas.

As the trees disappeared, the Primates had to adapt to the new conditions. They went down to the ground and, little by little, they left the trees.

Aegyptopithecus

The first primates that are known to move on the ground are the Aegyptopithecus. It is a catarrh from the Oligocene, now extinct, that walked on all fours and weighed about seven kilos.

The fossils of Aegyptopithecus have been found in Egypt.

Aegyptopithecus

By Nobu Tamura (http://spinops.blogspot.com) (Own work) [CC BY-SA 3.0 or GFDL], via Wikimedia Commons

Proconsul

The Proconsul appeared in the Miocene, and from this Primate a new evolutionary line emerged, that of the hominids. From the Proconsul's ancestors emerged the gibbons, the orangutans, the gorillas and chimpanzees, and the human species.

The Proconsul had some hominin traits, such as the absence of a tail and the presence of a thumb, but it also had other primitive features, such as a flexible spine and narrow thorax, like most monkeys.

They were still quadrupeds, Their diet was frugivorous.

Proconsul

By Nobu Tamura (http://spinops.blogspot.com) (Own work) [CC BY-SA 3.0 or GFDL], via Wikimedia Commons