Human skeleton up to 12,000 years old is excavated in Goiás – 05/13/2023 – Science

An excavation at an archaeological site in Serranópolis, in the southwest of Goiás (340 kilometers from Goiânia) revealed a complete fossil human skeleton with an estimated age of around 12,000 years.

If this is confirmed, it could represent the oldest known human for the Central Plateau region of the country.

The survey also found several archaeological artifacts, remains of bonfires and other more recent human remains, including ten complete heads, with an estimated age of 1,600 years.

Until now, estimating the age used dating coal samples that were close to the fossil. The skeleton was found lying on the left side of the body and in a flexed position (arms, legs, feet and hands bent towards the body), possibly the result of a burial.

Scientists now hope to analyze the bone material to be able to determine the exact age of the remains.

The work is coordinated by archaeologist Julio Cezar Rubin de Rubin, from PUC Goiás, and includes researchers from other Brazilian institutions, such as UnB (University of Brasília), UFC (Federal University of Ceará) and USP.

The excavation site is the archaeological site Gruta do Diogo 2, studied since the 1970s and where several ceramic and lithic (stone) objects, cave paintings and other traces of human occupation in the last ten thousand years had already been found.

“This work is the result of years of research in the region, but it did not start with our team. When starting new trips to the field in 2017, we tried to characterize the area well to know the best place to excavate”, said Rubin.

At the site, mapping was carried out using a device known as georadar —which emits frequency waves and in return receives a “signature” indicating the presence of materials of different compositions—, which identified the best sites for excavation.

The equipment detected anomalies in the rock, but was unable to state what they were, explains the field work coordinator, Jordana Barbosa.

The researchers then began to excavate in an area of ​​9 m^two and found the first traces of bonfires. “From there, we saw the hint of a skull. We enlarged the area to 18 m^twothus managing to isolate ten totally separate preserved skulls, with an estimated age of 1,600 years,” he said.

On the same wall there were coal samples with different calibrated ages, which allowed mapping the cave wall according to the stratigraphic layers (of sediment deposition): at about 50 cm depth, the layer had an estimated age of 1,000 to 2,000 years; at 66 cm, where the heads were found, the specimen indicated an age of approximately 1,600 years; reaching a depth of 1.70 m, it was already close to 9,000 years old.

Charcoal found near the foot of the fossil skeleton has been dated between 11,700 to 11,900 years old, so this is the estimated age attributed to the human.

“We are confident that the radiocarbon dating is correct and therefore this could indicate that the human skeleton is about 12,000 years old, not counting the other remains and objects found at the same site,” Rubin said.

“It is possible that the heads were placed there as a funerary ritual”, explains bioarchaeologist and USP professor Veronica Wesolowski. “There is variability in the forms of burial, the flexed position being very common among pre-colonial groups. The placement of stone blocks was intentional, part of the actual burial”, she says.

In March, she helped remove the remains, which were taken to the USP laboratory for DNA extraction from the petrous bone (from behind the ear) and teeth. The other elements are being studied at the Laboratory of Transdisciplinary Studies in Archeology at PUC Goiás.

The analyzes that can even confirm the composition of this group of humans that lived there through the genetic material are exactly the most expensive.

“Our luck was that we were able to complete five stages and we already have a sixth stage scheduled before the money runs out, but the greatest difficulty in continuing research like this is the lack of funding”, says Rubin.

If age is confirmed, this could be the oldest human in the region, according to Mercedes Okumura, a professor at USP’s Institute of Biosciences and coordinator of the Human Evolutionary Studies Laboratory, who did not participate in the study.

“We know that different human groups explored a great diversity of environments in the past. It is important, whenever possible, to obtain a dating of the bone itself in order to have greater certainty about this age of 12 thousand years”, he stated.

Matheus Pires, a zoologist and professor at PUC Goiás, is also part of Rubin’s team and studies the remains of animals and other traces left by humans in the caves.

“The cave is also a shelter for several animal species, not just humans. There are skeletons of mammals, birds and fish on the site, which may have accumulated naturally, or been collected and prepared by these peoples for food. “, he said. “And, in the deeper layers that are now within our reach, it is even possible to find bones of megafauna, such as giant sloths and armadillos”, he concludes.