Out of Africa: The Origin of Our Species (Part 1)

Aegyptopithecus & Kenyapitchecus

Note: I started reading Africa: A Biography of the Continent by John Reader. The following posts will basically summarize what I find interesting in the book as I’m reading it. The pictures are taken from Google Images, and some of the definitions are from Wikipedia. None of the ideas or thoughts are of my own.

Figure 1 - Aegyptopithecus

Aegyptopithecus = Ægypto + pithekos 

= from Greek Αίγυπτος (meaning: Egypt) + πίθηκος (meaning: primate or ape)

Aegyptopithecus is the earliest known candidate for ancestry of the ape and human lines (Figure 1). 

The fossil ape was found in the Fayum region of Egypt 35 million years ago (Figure 2). 

This was back when the African continent was still an island, cut off from Eurasia (i.e. Europe + Asia) and North America by sea (Figure 3). 

Figure 2 - Fayum, Egypt

Much of North Africa is desert land today, but back then it was a well-watered landscape, lush with forests that were gapped by open fields.

This small arboreal primate that lived in trees was about the size of a domestic cat; with long limbs, and all four capable of grasping branches as well as conveying food to the mouth. Their brain size was larger proportionately to body weight in comparison to other mammals of the time.

Evolution of species generally happens because of climatic change, and/or because of competition for resources. About 30 million years ago Africa, with the Arabian Peninsula attached, bumped to Eurasia.

Figure 3 - Earth at 60-40 million years ago

18 million years later (making it 17 million years ago) a baboon sized, quadruped, arboreal, fruit-eating primate called Proconsul existed on Rusinga Island close to the Kenyan shore of Lake Victoria (Figure 4). Four species of Proconsul have been classified to date: P. africanus, P. heseloni, P. major and P. nyanzae. They mainly vary in size.

Some of the same traits that the Proconsul carried were later seen in Kenyapithecus, which existed 15 million years ago. However, Kenyapithecus had a more modern set of teeth.

After Kenyapithecus, the fossil record that we have today of primates is almost nonexistent until about 5 million years ago when Australopithecus was found to exist. Footprints of Australopithecus afarensis that date from 3.7 years ago were found in Laetoli, Tanzania. A striding bipedal gait is unique to humans, so the Laetoli fossil footprint is the earliest known evidence to us of humanity’s existence. 

Figure 4 - Proconsul

So within those 10 million years (15 million years ago and 5 million years ago) the process of human evolution within the fossil record is still hidden. This is the period when our ancestral species acquired the upright stance and the striding bipedal gait.

To be continued...