1.8-million-year-old skull blends features of a number of early human species
By Brian Switek, National Geographic, Published October 17, 2013
A newly discovered skull, some 1.8 million years old, has rekindled debate over the identity of humanity’s ancient ancestors. Uncovered at the Dmanisi site in the Caucasus in Georgia, “Skull 5” represents the most complete jaw and cranium from a turning point in early human history.
Researchers, led by Georgian National Museum anthropologist David Lordkipanidze, first found the complete lower jaw of a fossil human in 2000. The cranium turned up five years later, at the fossil-rich Dmanisi site 96 miles southwest of Tbilisi, and is now being reported in the journal Science. The fossil’s importance was clear as soon as the team saw it, but required eight years of preparatory analysis.
That is because Skull 5 is what paleoanthropologists often refer to as a “mosaic,” or mixture of features seen in earlier and later humans. The skull’s face, large teeth, and small brain size resemble those of earlier fossil humans, but the detailed anatomy of its braincase — which gives clues to the wiring of the brain — is similar to that of a more recent early human species called Homo erectus. This combination of features has fueled a long-running discussion over whether the Dmanisi humans were an early form of Homo erectus, a distinct species called Homo georgicus, or something else.