Chindesaurus bryansmalli. Image credit: Petrified Forest National Park.
SciNews has a post about the rise of the dinosaurs during the Triassic. It seems that oxygen rose over 25% in 3 million years. That change might have led to the expansion of dinosaurs around 215 million years ago. The paper was presented at the 2019 Goldschmidt Conference in Barcelona, Spain.
A team of researchers from Rensselaer Polytechnic Institute and the University of Texas Austin has used a new technique to analyze tiny amounts of gas trapped inside 215-million-year-old rocks from the Colorado Plateau and the Newark Basin. Their results show that oxygen levels in these rocks leapt by nearly a third in just a couple of million years, possibly setting the scene for a dinosaur expansion into the tropics of North America and elsewhere.
“We tested rocks from the Colorado Plateau and the Newark Basin that formed at the same time about 621 miles (1,000 km) apart on the supercontinent of Pangea,” said Rensselaer Polytechnic Institute’s Professor Morgan Schaller, lead author of the study.
“Our results show that over a period of around 3 million years, the oxygen levels in the atmosphere jumped from around 15% to around 19%. For comparison, there is 21% oxygen in today’s atmosphere.”
“We really don’t know what might have caused this increase, but we also see a drop in carbon dioxide levels at that time.”
