(Rio de Janeiro) Torrential rains that caused historic flooding in southern Brazil have uncovered a dinosaur fossil dating back about 200 million years in a “very good state of preservation,” according to the team of scientists who discovered it.
This fossil was identified in May, in the town of Sao Joao do Polesine, about 300 km from Porto Alegre, in an area of pampas considered the Brazilian El Dorado of paleontology.
It dates from the Triassic period, from 250 to 200 million years before our era, before the Jurassic, made famous by the Hollywood saga Jurassic Park.
After four days of excavation, a team of paleontologists from the Federal University of Santa Maria (UFSM) managed to remove and transport to their research center the block of rock containing the fossilized skeleton.
According to the first observations of this famous center, it is a specimen of the family of herrerasaurids, bipedal carnivores with long tails that inhabited the lands where Argentina and Brazil are located today.
“Not only is it one of the oldest dinosaur fossils in the world, but it is in a very good state of preservation. It will give us a lot of information about the anatomy of these dinosaurs,” Rodrigo Temp Müller, head of the research, told AFP.
According to him, it is potentially the second most complete fossil known so far in the herrerasaurid family.
The first was discovered in the same region in 2014, allowing the identification of a new species with hooked claws, named gnathovorax cabreirai.
Several analyses will be necessary for scientists to clearly establish whether or not the fossil extracted from the rock in May belongs to this same species.
A “very meticulous, almost surgical” job, which could take “several months,” says Rodrigo Temp Müller.
“Even the smallest fragment can contain information that we could not obtain if it were damaged,” he insists.
At the end of the work, the research results must be published in a scientific journal.
Erosion accelerator
The pampas of southern Brazil, near the border with Argentina and Uruguay, conceal under its red earth a hundred deposits rich in fossils that reveal treasures of knowledge about the era of the first dinosaurs.
Torrential rains and floods that hit the region in May left more than 180 people dead and caused enormous material damage.
As far as paleontological research is concerned, these exceptional precipitations played a partly beneficial role, by “accelerating erosion”, thus revealing the fossil of the herrerasaurid family, which would not have been discovered until much later in normal times, according to Rodrigo Temp Müller.
But it also has drawbacks, with heavy rains “destroying a lot of material” from the fossils, especially small fragments.
This is why paleontologists closely monitor the deposits, looking for fragments exposed in the open air, and redouble their efforts during excavations to be able to recover fossils in the best possible condition.