Human Origins - Early Hominins

French paleoanthropologist Michel Brunet discovered this in July 2002. This is potentially the earliest record of the hominid family. This comes from the desertic region of Chad in central Africa.

The hominin features of this is that it had relatively small canines, a lack of sectorial complex, intermediate molar enamel thickness, anterior foramen magnum, reduced facial projection, and a well developed browridge. Non-hominin features of this is a small brain and basi-occipital, petrous, and temporal features.

This is the earliest known hominin from the Rift Valley of East Africa. The femur indicates bipedalism and the humerus and finger bone retains evidence of arboreal adaptations.

This is small-brained and the teeth indicate a diet like that of a chimp or baboon. They are more primitive bipedal gait than Australopithicus and are probable arboreal quadruped.

This is the oldest hominid known with undisputable evidence of bipedalism. It is found in Kanapoi and Allia Bay, Kenya 4.2-3.8 million years ago. They have a different canine/palate shape than those of the Australopithecus Africanus.

Raymond Dart's discovery of the "Taung Child" was the first early hominin found in Africa and the first discovery of a human genus different than our own. It had a small brain but clear evidence of bipedal behavior. This is a good example of mosaic evolution. This occurred in South Africa around 1924-1925. Also known as Australopithecus Africanus, the brain is endocast, the dental development, and the foramen magnum position are key points to take note of.

• A.

  True

• B.

  False

Paleontologist Robert Broom discovered four South African hominin cave sites in the 1930-1940s. Among these were the sites of Kromdraai and Swartkrans which yielded the first evidence of another new hominin genus, Paranthropus Robustus.

• A.

  True

• B.

  False

John Robinson, an anatomist who worked with Robert Broom in the 1950s, proposed the "dietary hypothesis" based on his studies of the South African hominins coining the terms "Gracile" and "Robust" based on the divergent adaptations of Australopithecus Africanus and Paranthropus Robust.

• A.

  True

• B.

  False

_________ __________ explored Olduvai Gorge from 1931-1968. There he discovered Zinjanthropus Boisei (same as Paranthropus Boisei).

The ________________ _________ has a sagittal crest. This has emphasis on mastication and the temporalis muscle fiber orientation.

This was founded 2.4 million years ago in the early "robust" form.

Don Johanson and Tim White described the species Australopithecus Afarensis based on discoveries at Hadar. In 1978, it was considered one of the earliest hominins ever found. The dental remains of this show a bi-modal distribution in size interpreted as sexual dimorphism within the species. It shares more features with chimps than humans.

• A.

  True

• B.

  False

This is a gracile australopithecine species whose fossils were discovered in 1996 by a research team led by Ethiopian paleontologist Berhane Asfaw and Tim White, an American paleontologist. The hominin remains are believed to be a human ancestor species and the final missing link between the Australopithecus genus and the human genus, Homo.