A team of Brazilian scientists have discovered the skeleton of what they believe is one of the world's oldest dinosaurs after heavy rains in the southern state of Rio Grande do Sul accelerated the natural process of erosion.
The fossil, found next to a reservoir in the municipality of São João do Polisín, is believed to be around 233 million years old, according to paleontologist Rodrigo Temp Muller, who led the Federal University of Santa Maria team that discovered the bones in May.
These claims have not been verified by other scientists or published in a scientific journal.
The researcher believes the dinosaur lived during the Triassic period (250 to 200 million years ago), when all the continents were part of a single landmass called Pangaea. Dinosaurs are thought to have first evolved around this time.
The apex predator discovered in Rio Grande do Sul belongs to a group known as Herrerasauridae — a family of dinosaurs that roamed the lands that now make up Brazil and Argentina, according to a fact sheet about the discovery shared with The Associated Press.
The size of the bones reveals that the dinosaur would have been about 2.5 metres long, according to the document.
Rodrigo Tempmüller said he and his team were “excited and very surprised” by their findings.
After about four days of drilling, the group of researchers brought a block of rock containing the sample to the lab, where they ran tests.
“At first it looked like a few isolated bones, but when we exposed the material, we could see that we had almost a complete skeleton,” Mueller said.
The expert believes that their discovery constitutes the second most complete skeleton of this type of dinosaur.
Researchers will now conduct investigations to determine whether the fossil belongs to an already known species or whether they have found a new one. This work is expected to take several months as the process is meticulous to ensure no damage is done.
Fossils are most likely to appear after rainfall, when water exposes the material by washing away the sediments covering it, in a phenomenon known as weathering.
Rio Grande do Sul experienced record rainfall earlier this year, causing devastating flooding in May that killed at least 182 people, according to a July 8 report from the state’s civil defense.
Extreme weather events are becoming more likely due to climate change, caused primarily by the burning of oil, gas and coal.
More fossils are being revealed by heavy rains, which have sparked a race against time to save the bones before they are destroyed, Muller said.
He added that his team noticed in the field “the leg bone and the pelvic bone in the pelvic area that were already destroyed by the rain.”
Mr Muller hopes the discovery will help clarify the origins of dinosaurs.
“Having such well-preserved new fossils certainly helps us better understand this still highly controversial topic,” he said.
