260m-year-old fossils discovered in a lost excavation site in Brazil

22 Jun 2022

Researchers conducting an excavation in the rediscovered site in Dom Pedrito, Brazil. Image: Ferraz et al

The fossils found in Brazil come from the end of the Permian period, when a massive extinction event decimated around 90pc of life on Earth.

Palaeontologists have discovered more than a hundred ancient fossils at a site in Brazil that was lost for more than 70 years.

The fossils are estimated to be around 260m years old, predating the first dinosaurs. They were in an ideal environment for preservation and were protected in thin layers of rock.

These fossils were recovered in a location known as Cerro Chato, which was discovered in 1951 by researchers who carried out geological mapping in the area.

Fossils were then collected and described, but technology at the time did not allow for the exact geographic referencing of the site, so the location was lost until 2019.

“For decades, the geographic location of this outcrop was unknown,” said researcher and paleobotanist Joseline Manfroi.

“It was sought as a true treasure hunt and, fortunately, after so long, we will have the opportunity to continue writing this history, through the fossil record.”

Two images side by side of a grassy location, with two people in each image. The image on the left is in black and white while the right is in colour.

Composition showing the excavation of the site in 1951 and its recent rediscovery. Image: Ferraz et al

The site near the city of Dom Pedrito is being researched by a team led by Joseane Salau Ferraz, a master’s student at the Federal University of Pampa in Brazil.

The researchers have discovered more than 100 specimens of plant fossils, including groups that belong to the ancestors of today’s conifers and ferns. The team has also discovered animal fossils such as fish and molluscs.

Ferraz estimates that the team has explored less than 30pc of the area, giving hope for further discoveries. She noted that the early expeditions were unable to explore the site too deeply due to the thick limestone in the area.

“If it’s difficult to work in a place like this today, even with technology, imagine the challenges that it represented in 1951,” Ferraz said.

The team said the fossils date to the end of the Permian period, which is marked by the most severe known mass extinction event when around 90pc of life on Earth was decimated due to intense weather disturbances.

“These studies will help us to retrieve information about the distribution of these plants around the world, as well as collecting evidence on what the climate was like at the time,” Ferraz said. “This new location will attract many eyes to our state.”

The site was rediscovered with the participation of researchers from the Federal University of Rio Grande do Sul, the University of Vale do Taquari and the Federal University of Pampa. The current research team has been funded to continue the excavations with a three-year projection for field activities.

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Leigh Mc Gowran is a journalist with Silicon Republic