One of the earliest known ancestors of the human species is the Australopithecus. The oldest known specimen that belongs to the Australopithecus branch is Lucy, discovered in Ethiopia in 1974 and considered to have lived approximately 3.2 million years ago.
This made Lucy the oldest known human ancestor. However, researchers discovered 21 years ago skeleton in South Africa they believed was actually older than that of Lucy.
The scientists named the skeleton Little Foot and according to a new study, it appears that Little Foot lived more than 3.67 million years ago and could be one of the first Australopithecus.
In the vicinity of the area where Little Foot’s skeleton was unearthed, the researchers also found stone tools that date back more than 2.18 million years ago, and considered to be the oldest stone tools ever discovered so far.
The remains of Little Foot were discovered by Ronald Clarke, professor at the Evolutionary Studies Institute from the University of the Witwatersrand.
Professor Clarke explained that Little Foot proves the fact that later species of hominids, like Australopithecus africanus and Paranthropus did not necessarily come from Australopithecus afarensis.
Clarke said that scientists construct evolutionary scenarios based on the fossils they have discovered so far and those fossils are not many.
Little Foot’s age could prove the possibility that there could have been many other species belonging to the Australopithecus group living in much wider African regions.
Darryl Granger, a researcher at the University of Purdue, said that Little Foot could have existed between 2 and 4 million year ago, around the time when Australopithecus existed on our planet.
The paleontologist who discovered Little Foot’s remains decided the bones are more than 3 million years old.
In order to determine Little Foot’s approximate age, the researchers used a special dating technique that was originally designed by NASA to analyze solar wind samples taken from the genesis mission.
This dating method is called “isochron burial dating” and it utilizes radioisotopes taken from the rock samples found near where the skeleton was discovered. This way the researchers can determine how long the rocks have been under the ground or hidden from sunlight.
Granger said that this dating technique, although expensive and requires a lot of work, is the future of dating methods because of its accuracy.
This is the second time Little Foot’s remains have been dated because the first one was questioned by many scientists.
Image Source: news.sciencemag
Joe Hennessey
