A lower jaw bone and five teeth have been discovered on a hillside in Ethiopia. They are the oldest remains ever found belonging to the genus Homo, the lineage that ultimately led to modern humans.
Fossil hunters spotted the jaw poking out of a rocky slope in the dry and dusty Afar region of the country, about 250 miles from Addis Ababa in 2013, and they were archaeologically studied, and dated, ISNA reported.
The research team believes the individual lived about 2.8 million years ago, when the now parched landscape was open grassland and shrubs nourished by tree-lined rivers and wetlands.
The remains are about 400,000 years older than fossils which had previously held the record as the earliest known specimens on the Homo lineage.
The discovery sheds light on a profoundly important but poorly understood period in human evolution that played out between two and three million years ago, when humans began the crucial transformation from ape-like animals into forms that used tools and eventually began to resemble modern humans. This is the first inkling of that transition to modern behavior.
The new fossil has a handful of primitive features in common with an ancient forerunner of modern humans called Australopithecus Afarensis. The most well-known specimen, the 3m-year-old Lucy, was unearthed in 1974 in Hadar, is the latest fossil with more modern traits. Some are seen only on the Homo lineage, such as a shallower chin bone.
With this jaw bone archaeologists have figured out where that trajectory started. They believe in all likelihood a major adaptive transition indicates that this is the first Homo.
