By IB Times Staff Reporter: Subscribe to IB's RSS feed
September 10, 2011 11:42 AM EDT
Human's oldest direct ancestors may have swung from tree branches, and are believed to be some 2-million-year-old long-armed, diminutive bodied chimp-like creatures with modern hands, ankles and pelvis.
Researchers on Thursday announced they have confirmed the age of new fossils that may be forerunners to modern humankind. They say the 1.98-million-year-old bones from a pair of primate fossils are giving new knowledge into the evolution of modern man.
Until the recent find, it was widely believed that the first tool-maker was Homo habilis because of a set of 21 fossilized hand bones that were found in Tanzania dating back 1.75 million years, along with a collection of artifacts.
But researchers perform closer examination and did further dating of the two fossilized skeletons, Australopithecus sediba, found in South Africa about two years ago, and described it for the first time last April.
Australopithecus sediba is a type of pre-human, which scientists believe could be an ancestor of modern Homo sapiens. It possessed the characteristics of older members of the Australopithecus family, but also has much in common with the newer Homo class that includes human beings today.
Follow us
Researchers did a series of studies on newly exposed cave sediments at the Malapa Cave site in South Africa, where the fossils were found, and were able to determine the more precise age at 1.98 million years old.
If their calculations are correct, it means that the Malapa site is one of the best dated early human sites in the world.
It seems like the fossils were deposited in the Malapa Cave during a 3,000-year period around 1.98 million years when the Earth's magnetic field reversed itself by 180 degrees and back again, researchers say,
"Knowing the age of the fossils is critical to placing them in our family tree, and this new age means that Australopithecus sediba is the current best candidate for our most distant human ancestor," says Dr. Robyn Pickering of the University of Melbourne's School of Earth Sciences. "The results of these studies present arguably the most precise dates ever achieved for any early human fossils."
Pickering is a lead researcher who was involved in the dating of the flowstone surrounding the fossils.
The University of Melbourne conducted uranium lead dating of the flowstone. This was coupled with palaeomagnetic analysis sediments surrounding the fossils, which was done by La Trobe University in order to provide the tightly constrained new age.
The team pinned down the age of the fossils to within 3000 years of 1.98 million years, which they say is a massive advance on the age range of around 200,000 years from the 2010 estimate.
Pickering said researchers had long been searching for fossils from this time period to answer questions about the beginnings of our own genus Homo.
Some have said the newly found bones and skull could be a "game-changer" in understanding human evolution.
We value your privacy. Your email address will not be shared.
