Researchers in South Africa recently made a major discovery that could change the previously understood timeline of human existence. The discovery comes as new tests on some recovered specimens show they are much older than previously thought, BBC News reports.
Fossils of early human ancestor Australopithecus africanus found in caves near Johannesburg, South Africa, are thought to date back to 2.6 million years ago. However, new tests of the sediment where the specimen was found found it to be closer to 3.4 million to 3.7 million years old, CNN reported.
This is a huge difference, changing the time frame in which species like Australopithecus africanus were thought to have existed, and now seems to indicate that they overlapped with other species Australopithecus afarensis , the famous fossil Lucy being among them a part of. Until now, it has been thought that Australopithecus africanus is a descendant of Australopithecus afarensis, but this new information calls that assumption into question.
New test puts dating controversy to rest
The cave has been the location where hundreds of Australopithecus fossils have been found since the site was discovered in 1936, CNN reports. Since then, major fossil discoveries including an almost complete female skull, known as "Mrs. Price", and an almost complete skeleton known as Littlefoot have been found there (via BBC News). However, the anthropological community is divided over the true age of these fossils.
"Sterkfontein has more Australopithecus fossils than anywhere else in the world," said Daryl Granger, professor of Earth, atmospheric and planetary sciences in Purdue University's College of Science. "But it's hard to put a good date on them. People looked at animal fossils found near them and compared the ages of cave features like flowstones and came up with a range of different dates. What our data do is resolve These disputes. It shows that these fossils are ancient - much older than we first thought."
How did the researchers come to this conclusion?
tested the sediments surrounding where the fossils were found, as well as the fossils themselves, and found that they were between 3.4 million and 3.6 million years old. According to CNN, the dating process used the cosmogenic nuclide , which is a rare radioactive particle produced inside minerals by cosmic rays. This is important because it puts these Australopithecus fossils closer to the end of the Australopithecus era than its beginning, as previously thought.
"Our ages suggest this cannot be true as they are nearly the same age," Granger said in a statement. "There must have been an older common ancestor. It also provides more time for the evolution of the South African species and reopens the discussion of the role that the South African species played in later humans, such as Parahuman."
This is not Grant Jay used this method for the first time to make a breakthrough discovery. In 2014, Granger discovered that dating could be done very accurately by measuring small amounts of aluminum-25, a cosmogenic nuclide. This allows researchers to date previously very difficult sites. Is this another step forward in exploring the unknown?
