Cradle of humanity: older fossils found

In South Africa, exactly in the limestone caves of Sterkfontein, numerous bones of ancient Australopithecus hominids have been found. Thus the location was called the cradle of mankind,
essential to human evolution. The remains date from almost 4 million years ago, they are older than the famous
person known as Lucy.

Most of the Sterkfontein finds were collected in a cavern fill called Lid 4. In simpler words, a material that filled what was previously a cavity, becoming a sedimentary deposit. Thus it simultaneously hid and preserved ancient remains of humanoids.

For analysis of the flux rock or other nearby bones, the team looked at the rock where they were
processed the remains of theAustralopithecus. He eventually discovered the radioactive decay of two rare isotopes

in quartz.

These radioactive isotopes, known as cosmogenic nuclides, are produced by high-energy cosmic radiation reactions near the surface of the ground, and their radioactive decay dates back to when the rocks were buried in the cave when they fell into the entrance along with the fossils. The restoration of Australopithecus-bearing fillings in the Sterkfontein Caves will no doubt reignite the debate about the various characteristics of the Australopithecus at Sterkfontein and whether there may have been South African ancestors of later hominids.

Darryl Granger, a geologist and geophysicist at Purdue University

From the latter, the research team understood that Australopithecus-bearing sediments are traceable
between 3.4 and 3.7 million years ago. All this means that the recovered remains are at the beginning of the era
Australopithecus and not at the end of that period. So it is not as previously thought. Such an
discovery is vital to better understand human evolution.