Dinosaurs appeared 5-10 million years earlier than previously thought, according to new research.
Scientists from Argentina, Brazil, California and the Utah Museum of Natural History have found that the first dinosaurs appeared between 234 and 236 million years ago, in the Late Triassic period. This is 5-10 million earlier than previous estimates.
“We have found that the geological age of these precursor dinosaurs is much younger than previously thought. It turned out to be unexpected, said Randall Irmis, professor and curator of paleontology.
The data were obtained from radioisotope analysis of zirconium crystals found in sediments of the Chanares Formation.
Photo: Victor Leshyk
This formation is located in the northwest of Argentina, it is formed by a 75-meter geological layer of sedimentary rocks. Among the sedimentary rocks are numerous dinosauromorph fossils, from which, according to scientists, dinosaurs originated.
“In other basins, dinosaur ancestors, early dinosaurs and other fauna did not live in the same place. In the basin where the Chanyares Formation is located, hundreds of meters of sediment can be traced over time. Because of this, the probability of error is very small, because you can see the complete history of living things in the same basin,”says Claudia Marsicano from the University of Buenos Aires.
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Marsicano is the leader of a study that was recently published on the website of the US National Academy of Sciences.
According to the group of scientists, the study calls into question the age of other formations with fossils that date back to the Middle Triassic period.
“It is possible that the Santa Maria Formation in southern Brazil and the Karu Formation in South Africa, like Chanyares, are from the Late Triassic period,” the scientists said.
"We have a lot to explore," Randall Irmis told Nature Magazine. "It's really exciting."