Researchers have unearthed fossilized teeth in Ethiopia dating to approximately 2.65 million years ago from a previously unknown species in our evolutionary lineage. This new species belongs to the genus Australopithecus and lived in the same place and time as the earliest-known member of the genus Homo.
The scientists, working in the Ledi-Geraru research project area, discovered ten fossilized teeth from two distinct individuals in northeastern Ethiopia’s Afar Region. The newly found teeth bear unique traits indicating that they belong to a seventh distinct species of Australopithecus, an important early human ancestor.
Researchers also unearthed three other teeth dating to approximately 2.59 million years ago from the oldest-known species of Homo ever found. These new dental fossils provide critical insight into a poorly understood period of human evolution, a crucial time of great change.
The close age of the fossils suggests this Australopithecus species coexisted in this region with the early Homo species, raising questions about resource competition. This discovery indicates that four different hominins inhabited East Africa at the same time, demonstrating a complicated and non-linear evolutionary process.
This finding reinforces the idea that human evolution is not a single lineage, but rather a branching process with multiple species living simultaneously. Scientists are currently analyzing the teeth to determine if the two species had similar diets, which could indicate they competed for the same food sources.
The researchers determined the precise age of the teeth using a technique that dated feldspar crystals in volcanic ash via radioactive argon decay. At that time, the Afar Region was a vegetated landscape with rivers and shallow lakes, populated by a splendid array of large animals.