![]() ![]() “But it’s hard to get a good date on them. “Sterkfontein has more Australopithecus fossils than anywhere else in the world,” Granger said. The concrete-like matrix that embeds the fossil, called breccia, is the material Granger and his team analyzed. A more accurate method is to date the actual rocks in which the fossils were found. But bones can shift in the cave, and young flowstone can be deposited in old sediment, making those methods potentially incorrect. ![]() They typically use other animal fossils found around the bones to estimate their age or calcite flowstone deposited in the cave. In South Africa – especially in a cave – the scientists don’t have that luxury. Researchers use those layers to estimate how old a fossil is. In East Africa, where many hominin fossils have been found, the Great Rift Valley volcanoes lay down layers of ash that can be dated. ![]() Understanding the dates of the fossils here can be tricky, as rocks and bones tumbled to the bottom of a deep hole in the ground, and there are few ways to date cave sediments. Sterkfontein is a deep and complex cave system that preserves a long history of hominin occupation of the area. Dinkinesh, who hails from Ethiopia, is 3.2 million years old, and her species, Australopithecus africanus, hails back to about 3.9 million years old. That age places these fossils toward the beginning of the Australopithecus era, rather than near the end. In a new study published on June 27, 2022, in the Proceedings of the National Academy of Sciences, Granger and a team of scientists including researchers from the University of the Witwatersrand in Johannesburg, South Africa and the University Toulouse Jean Jaurès in France, have discovered that not only Little Foot, but all of the Australopithecus-bearing cave sediments date from about 3.4 to 3.7 million years old, rather than 2-2.5 million years old as scientists previously theorized. Credit: Purdue University photo/Lena Kovalenko New data pushes its age back more than a million years, to 3.67 million years old. Paleoanthropologists and other scientists have studied Sterkfontein and other cave sites in the Cradle of Humankind for decades to shed light on human and environmental evolution over the past 4 million years.ĭarryl Granger of Purdue University developed the technology that updated the age of an Australopithecus found in Sterkfontein Cave. Ples, and the nearly complete skeleton known as Little Foot. Since then, hundreds of Australopithecus fossils have been found there, including the well-known Mrs. Hominins include humans and our ancestral relatives, but not the other great apes. Sterkfontein was made famous by the discovery in 1936 of the first adult Australopithecus, an ancient hominin. The “ Cradle of Humankind” is a UNESCO World Heritage Site in South Africa that comprises a variety of fossil-bearing cave deposits, including those at Sterkfontein Caves. ![]() This would make them even older than Dinkinesh, also called Lucy, the world’s most famous Australopithecus fossil. Now, a dating method developed by a Purdue University geologist just pushed the age of some of these fossils found at the site of Sterkfontein Caves back more than a million years. Scientists have studied these fossils of early human ancestors and their long-lost relatives for decades. The earth doesn’t give up its ancient secrets easily – not even in the “Cradle of Humankind” in South Africa, where a wealth of fossils relating to human evolution have been discovered. Credit: Jason Heaton and Ronald Clarke, in cooperation with the Ditsong Museum of Natural History The new date overturns the long-held concept that South African Australopithecus is a younger offshoot of East African Australopithecus afarensis. The Sterkfontein cave fill containing this and other Australopithecus fossils was dated to 3.4 to 3.6 million years ago, far older than previously thought. Pictured are four different Australopithecus crania that were found in the Sterkfontein caves, South Africa. ![]()
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