Primate dating techniques
The exits the braincase) may suggest a habitually upright posture.The most remarkable aspect of this skull is the broadness and flatness of its face—something previously associated with much more recent hominins—in conjunction with a smaller, ape-sized braincase.
may have originated as early as about 2.8 mya, though the record during this time is tantalizingly fragmentary.Viewed this way, , both known from South and East African sites.This early radiation (diversification) of hominins, of which the latest survivors lived as recently as about 1.5 mya, made for a rather motley assortment.more closely than any other known living organisms, but at the time it was a daring act to classify human beings within the same framework used for the rest of nature.Linnaeus, concerned exclusively with similarities in bodily structure, faced only the problem of distinguishing extend the span of this species far back into time to include many anatomically distinctive fossils that others prefer to allocate to several different extinct species.These fossils, along with the slightly older trails of footprints found at , Tanzania, prove that early hominins were upright bipeds when on the ground.
However, they also retained many reminders of their tree-dwelling ancestry, especially their rather long arms, short legs, narrow shoulders, and long grasping extremities.
The design of her pelvis and feet are suggestive of bipedal locomotion.
However, other skeletal elements indicate that she spent much of her time clambering through the branches of trees.
In contrast, Lucy’s skeleton is 40 percent complete and dates to about 3.2 mya.
Lucy’s pelvis is more humanlike, and the design of her knee joint suggests that she walked upright in a manner similar to that of modern humans.
In contrast, a majority of paleoanthropologists, wishing to bring the study of hominins into line with that of other mammals, prefer to assign to to calculate how long species had been separated from a common ancestor.