Question

Write a broad description of how the cranial characteristics of the forehead changed over time. Going from Sahelanthropus tchadensis to Homo sapiens.

Answer 1

Sahelanthropus tchadensis is believed to be the oldest known species on the human lineage. The species inhabited western central, africa 7 million years age. It is thought the species lived in a diverse habitat, including forestes and grassland. Sahelanthropus features a mix of ape like and human like characteristics. Like apes it had a small brain, sloping face and large browridges. However it also had small canines and a spinal cord opening underneath its skull suggesting it may have been bipedal. sahelanthropus is currently the oldest known hominid to show adaptations for walking on two legs. The foramen magnum is located further forward than in any other primate species except humans. This might indicate the species head was held on an upright body. The first and only known fossil remain of sahelanthropus comes from nine cranial specimens from chad, In 2001 these remains were discovered by a team of scientists led by french paleontologist michel brunet. The specimen is nicknamed toumai. The earliest human ancestors were once thought to have evolved in eastern africa but the disco very of toumai in chad showed that earlier hominins were more widely distributed.

Our skulls are different from ancient ancestors. Only a few difference showed between the modern skull and the earlier human ancestors. The major change was in the cranial base, the plate of the bone that forms both the roof of our faces and the floor of our brain case. It shows empty eye socket and bony platform. The mordern skulls rounder than the ancient skull and the flexon, which coincided with a forward extension of the cranial base, also moved faces under the front part of the brain and eliminated heavy brow ridges.