However, fossil information from that time in other regions is much thinner and it is not known whether the pattern seen in North America is representative of global dinosaur diversity. afterward.
Eggs and eggshell fragments represent the last 2 million years of the dinosaur era, with fossils representing each 100,000 year period. The research involved gathering detailed age estimates of rock layers by analyzing and applying computer models to more than 5,500 geological samples.
Analysis found full eggs and eggshell fragments from The researchers said there were only three species of dinosaurs, which suggests that dinosaur biodiversity was low during that time period.
Macroolithus yaotunensis and Elongatolithus elongatus belong to a group of toothless dinosaurs known as oviraptors, while the third, Stromatoolithus pinglingensis, is a herbivorous dinosaur, or a member of the group of duck-billed dinosaurs.
Researchers say their findings from fossil eggs are consistent with fossil dinosaur bones found in the same area and around, although they have discovered several other dinosaur bones from the area that suggest Tyrannosaurs and sauropods also lived in this area between 66.4 million and 68.2 million years ago.
“Our results support a long-term decline in global dinosaur biodiversity prior to 66 million years ago, which likely set the stage for the mass extinction of nonavian dinosaurs,” the study said. end of the Cretaceous period”.
Most dinosaurs are extinct, but several smaller, birdlike species survived and evolved into the birds we see today.
“These results also contradict what emerges from egg carcasses and the diversity of bones, teeth and other remains found in places like Spain, (and) other remains,” he said by email. What we know is based on North American records. “So I believe these authors are misinterpreting these signals.”
He still believes the asteroid strike is the real driving force of the extinction of the dinosaurs.
“Dinosaurs were probably very good and varied and if it weren’t for the late Cretaceous asteroids (they) might as well dominate today as far as we know.”