Ardipithecus Had Humanlike Skull: Fossil Analysis Pegs East African Species as Hominid
Bower, Bruce, Science News
One of the most controversial proposed members of the human evolutionary family, considered an ancient ape by some skeptical scientists, is the real hominid deal, an analysis of a newly reconstructed skull base finds.
By 4.4 million years ago, Ardipithecus ramidus already possessed a relatively short, broad skull base with a forward-placed opening for the spinal cord, an arrangement exclusive to ancient hominids and people today, William Kimbel of Arizona State University in Tempe reported on April 11.
Although features of the skull's floor evolved substantially in Homo species leading to modern humans, Kimbel said, those changes appeared piecemeal starting at least a couple of million years earlier in hominids such as Ardipithecus.
A. ramidus is best known by the partial skeleton of an adult female, dubbed Ardi, described in 2009 (SN: 10/24/09, p. 9). Elements of Ardi's build related to tree climbing, such as grasping feet and an elongated lower hip bone, have raised suspicions that she and her kind come from apes that evolved a rudimentary ability to walk upright without being hominids. However, Ardi's discoverers argue that she was a hominid whose species split time between slow, awkward walking and shuffling along tree branches while grabbing upper branches for support. …