Early-human fossils called “small-brained, tree-climbing, meat-eating midgets”

William Atkins
Saturday, 22 September 2007 21:15

Science - Biology

Researchers have found the skeletons of three adults and one teenager in the central Asian country of Georgia, which are believed to be 1.77-million-year-old examples of the earliest known genus Homo ever found outside of Africa. They contain both apelike and human features.       

The research team was headed by David Lordkipanidze of the Georgian National Museum in Tbilisi, Georgia. In total, they recovered 33 lower-body bones from at least three adults and one teenager at a site called Dmanisi, which is near the town of Dmanisi, in Georia—about 60 miles (100 kilometers) southwest of the capital city of Tbilisi. Many archaeological studies have been performed at the area around the town of Dmanisi.

The discovered skeletons imply that the humanoids would have had small brains (about one-half to two-thirds the size of modern humans) and small bodies when compared to early Homo erectus fossils found in Africa. The skeletons would have had a height of about 4.7 to 5.4 feet (1.45 to 1.66 meters) and weighed about 88 to 110 pounds (40 to 50 kilograms).

The newly discovered fossils also reveal ape-like arms and hands, which would be well suited to climbing and living in trees.

However, they also had long legs, foot bones, and a spine that were developed to be able to walk and run long distances—features seen in modern humans.

Lordkipanidze states, “If this [group] is Homo erectus, it is the most primitive and oldest one known.” Although the fossils could be a very early form of Homo erectus that left Africa for Asia, such a conclusion is still speculation, according to Lordkipanidze.

The findings of the Lordkipanidze team are written up in the September 20, 2007 edition of the journal Nature under the title “Postcranial evidence from early Homo from Dmanisi, Georgia” (Nature 449, 305-310).

The abstract of the paper states, “The Plio-Pleistocene site of Dmanisi, Georgia, has yielded a rich fossil and archaeological record documenting an early presence of the genus Homo outside Africa. Although the craniomandibular morphology of early Homo is well known as a result of finds from Dmanisi and African localities, data about its postcranial morphology are still relatively scarce. Here we describe newly excavated postcranial material from Dmanisi comprising a partial skeleton of an adolescent individual, associated with skull D2700/D2735, and the remains from three adult individuals. This material shows that the postcranial anatomy of the Dmanisi hominins has a surprising mosaic of primitive and derived features. The primitive features include a small body size, a low encephalization quotient and absence of humeral torsion; the derived features include modern-human-like body proportions and lower limb morphology indicative of the capability for long-distance travel. Thus, the earliest known hominins to have lived outside of Africa in the temperate zones of Eurasia did not yet display the full set of derived skeletal features."

Additional information on this discovery is found in the Science News article “Walking Small: Humanlike legs took Homo out of Africa” and the AFP article “Fossils raise fresh questions over mankind's evolutionary saga”.