Homo georgicus

Homo georgicus is a species of Homo that was proposed in 2002. It is based on fossil skulls and jaws found in Dmanisi, Georgia in 1999 and 2001, which seem intermediate between Homo habilis and H. erectus.

Homo georgicus Temporal range: Pleistocene
Skull D2700 (Replica)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Primates
Family:	Hominidae
Genus:	Homo
Species:	H. georgicus
Binomial name
†Homo georgicus Vekua et al., 2002

Fossil skull from Dmanisi.

A partial skeleton was discovered in 2001. The fossils are about 1.8 million years old. The remains were first discovered in 1991 by Georgian scientist, David Lordkipanidze, accompanied by an international team which unearthed the remains. Implements and animal bones were found alongside the ancient human remains.

At first, scientists thought they had found mandibles and skulls belonging to Homo ergaster, but size differences led them to name a new species.

Interpretations

Location of discovery

Drawing of Dmanisi skull D-2282

Small skull

At around 600 cm³ brain volume, the skull D2700 is dated to 1.77 million years old and it is in good condition. The cranium was the smallest and most primitive Hominin skull ever discovered outside of Africa.

In Africa, the Australopithecines and early Homo represent two distinctive evolutionary paths sharing a common ancestor. In Georgia the specimens, with a brain half the size of anatomically modern humans, were the smallest found until the discovery of Homo floresiensis on the island of Flores in 2003.

There is a strong sexual dimorphism present, with males being significantly larger than females. This is a primitive trait, less obvious in more recent human species in Europe (i.e. Homo antecessor, Homo heidelbergensis and Homo neanderthalensis).

The small size of this species contrasts with the much larger size of Homo erectus. H. georgicus was the first species of Homo to settle in Europe, some 800,000 years before H. erectus.

Later, four fossil skeletons were found, showing a species primitive in its skull and upper body but with relatively advanced spines and lower limbs, providing greater mobility. They are now thought to represent a stage soon after the transition between Australopithecus and Homo erectus, and have been dated at 1.8 million years before the present. The assemblage includes one of the largest Pleistocene Homo mandibles (D2600), one of the smallest Lower Pleistocene mandibles (D211), a nearly complete sub-adult (D2735), and a specimen without teeth (D3900).

Classification

H. georgicus is often classified as Homo erectus georgicus. The classical textbook definition of H. erectus included a brain size range of between 900–1150 ccs. If the georgicus specimens and the Flores specimens (Homo floresiensis) are included in H. erectus, then the range of brain capacities is two-fold, from 600 ccs to 1150 ccs. Also, Homo ergaster is also considered by some to be a subspecies of H. erectus. Size has something to do with it: both the georgicus and floriensis were much smaller than the classic erectus, which was as tall as modern man. The classification of all these species or subspecies is provisional at present, and still being debated.

Other websites

• Foley, Jim 2009. "Skull D2700". TalkOrigins Archive. Retrieved 9 September 2009.