Washington, D.C-- A nearly complete fossil cranium and another skullcap, representing the earliest known human ancestors from Eurasia, may also belong to the first hominid species to journey out of Africa. A team of Georgian, German, French and U.S. researchers describe these "First Eurasians" from the site of Dmanisi in the Republic of Georgia in the 12 May issue of Science.
The Science authors say that these 1.7 million year-old fossils are the first fossils discovered outside of Africa to show clear signs of African ancestry. The age and skeletal characteristics of the Dmanisi skulls link them to the early human species Homo ergaster, a species that some researchers believe is the African version of Homo erectus.
Most scientists think that Homo erectus was the first hominid species to leave the African continent, although the exact identity of these ancestral travelers and the timing of their departure has been hotly debated for decades. Under the classic scenario, Homo erectus, armed with an advanced tool kit called the Acheulean or hand-ax tradition, became the first human species capable of braving an array of challenging environments outside the African cradle.
The Dmanisi fossils, however, may undermine this tale of the technologically triumphant hominid. Stone tools found with the two skulls are of the less sophisticated "pebble-chopper" type that preceded the Acheulean in Africa, and the site itself is older than any known Acheulean tools. The tools, along with details of the fossils' anatomy and the age of the site, "argue for early, pre-Acheulean migrations out of Africa," say the authors.
The fossils were retrieved during the course of archaeological investigations of a medieval castle at Dmanisi. Meticulous geological investigation confirms that the human fossils, accompanying animal bones, and tools come from sediment-filled, irregularly-shaped "burrows," scooped out of the ancient
'"/>
Contact: Ginger Pinholster
gpinhols@aaas.org
202-326-6421
American Association for the Advancement of Science
11-May-2000