A mysterious cranium with a stalagmite rising out of its head is about 300,000 years outdated and neither human nor Neanderthal, a brand new research finds.
The cranium was reportedly found hooked up to the wall of Petralona Cave in northern Greece in 1960. Researchers have since argued about its place on the human household tree and had hassle determining its age — till now.
In the new study, published online Aug. 14 in the Journal of Human Evolution, researchers dated calcite (a mineral type of calcium carbonate usually present in caves) protruding out of the cranium to search out that it was not less than 277,000 years outdated. They do not know exactly how lengthy the cranium was within the cave earlier than it started buying calcite, however the brand new estimate helps slender down earlier makes an attempt thus far the cranium, which have ranged from 170,000 to 700,000 years outdated.
The findings assist earlier recommendations that the Petralona particular person lived in Pleistocene-era Europe alongside Neanderthals, however was a part of a special human group, broadly referred to as Homo heidelbergensis.
The Petralona fossil is distinct from H. sapiens and Neanderthals, research co-author Chris Stringer, a paleoanthropologist on the Natural History Museum in London, advised Live Science, “and the new age estimate supports the persistence and coexistence of this population alongside the evolving Neanderthal lineage in the later Middle Pleistocene of Europe”.
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The Petralona cranium, generally referred to as the “Petralona Man,” was virtually actually male based mostly on the fossil’s measurement and robustness, based on Stringer. He additionally mentioned that the cranium’s tooth had average put on, so it possible belonged to a younger grownup.
While information of the cranium’s discovery are poor, Stringer famous that there is proof to assist the concept that it was caught to the wall by calcite encrustations — the identical variety that had been protruding out of the cranium.
To estimate the age of the calcite, researchers used a way referred to as uranium-series relationship. Calcite comprises a small quantity of uranium, which decays into one other radioactive factor referred to as thorium over a set interval. This fastened fee of decay signifies that researchers can calculate ages based mostly on the calcite’s ratio of uranium to thorium. The cranium calcite dates again to round 286,000 years in the past, with a excessive diploma of confidence that it is not less than 277,000 years outdated.
The relationship analysis additionally instructed that calcite grew fairly quickly within the cave. Stringer famous that it possible did not take lengthy for the cranium to accumulate its first layer of calcite, which might imply the cranium is round 300,000 years outdated. However, the cranium might be older than 300,000 years outdated if the calcite took longer to type.
The estimate of 300,000 years outdated suits with Stringer and colleagues’ evaluation of an analogous fossil from Zambia in Africa often called the Kabwe cranium. Their 2019 research dated the Kabwe cranium, which is commonly assigned to H. heidelbergensis, at 299,000 years outdated.
“That fossil is closely comparable to the Petralona one, and I would classify them both as Homo heidelbergensis,” Stringer mentioned.