文档介绍：Antiquity of Humanity
Basal Hominids
Genus Paranthropus
Theories of Human Origins
Cosmologies
Religious explanations for our origins, ie.
Genesis
Mayan Origin Myths
Scientific explanations
Using Scientific Method to explain origins
Evolution
Theory of Natural Selection
Basal Hominids (6-4 mya)
Sahelanthropus tchadensis
Ardipithecus ramidus
Australopithecus anamensis
Orrorin tugenensis
s/homs/ Copyright © Jim Foley
Sahelanthropus tchadensis
This species was named in July 2002 from fossils discovered in Chad in Central Africa ( et al. 2002, Wood 2002).
It is the oldest known hominid or near-hominid species, dated at between 6 and 7 million years old.
This species is known from a plete cranium nicknamed Toumai, and a number of fragmentary lower jaws and teeth. The skull has a very small brain size of approximately . It is not known whether it was bipedal.
S. tchadensis has many primitive apelike features, such as the small brainsize, along with others, such as the brow ridges and small canine teeth, which are characteristic of later hominids.
This mixture, along with the fact that es from around the time when the hominids are thought to have diverged from chi
mpanzees, suggests it is close to mon ancestor of humans and chimpanzees.
Sahelanthropus tchadensis
Ardipithecus ramidus
This species was named in September 1994 (White et al. 1994; Wood 1994). It was originally dated at million years, but has since been discovered to far back as million years.
Most remains are skull fragments. Indirect evidence suggests that it was possibly bipedal, and that some individuals were about 122 cm (4'0") tall.
The teeth are intermediate between those of earlier apes and A. afarensis, but one baby tooth is very primitive, resembling a chimpanzee tooth more than any other known hominid tooth.
Other fossils found with ramidus
indicate that it may have been a forest dweller. This may cause revision of current theories about why hominids became bip