Evolution

Sahelanthropus tchadensis is an extinct hominid species that is dated to about 7 million years ago. Whether it can be regarded as part of the Hominina tree is unclear; there are arguments both supporting and rejecting it. Another complication in its classification is that it is older than the human–chimpanzee divergence (estimated to 6.3 to 5.4 million years ago) seen in genetic data,[2] and that there are few if any specimens other than the partial skull known as Toumaï.

Existing fossils – a relatively small cranium nicknamed Toumaï ("hope of life" in the local Dazaga language of Chad in central Africa), five pieces of jaw and some teeth make up a head that has a mixture of derived and primitive features. The braincase, being only 320 cm³ to 380 cm³ in volume is similar to that of extant chimpanzees and is notably less than the approximate human volume of 1350 cm³. The teeth, brow ridges, and facial structure differ markedly from those found in Homo sapiens.

The Taung Child — or Taung Baby — is the fossilized skull of a young Australopithecus africanus individual. It was discovered in 1924 by quarrymen working for the Northern Lime Company in Taung, South Africa. Raymond Dart (1893–1988) described it as a new species in the journal Nature in 1925.

In the early 20th century, workers at limestone quarries in southern Africa routinely uncovered fossils from the tufa formations they mined. Many were of extinct fauna, which included baboons and other primates, and the more complete or somehow more interesting fossils were kept as curios by the Europeans that managed operations.[1]

In 1924, workers at the Buxton Limeworks near Taung, South Africa showed a fossilized primate skull to E.G. Izod, the visiting director of the Northern Lime Company, the managing company of the quarry. The director gave it to his son, Pat Izod, who displayed it on the mantle over the fireplace.