However, fossil records from other regions are very thin, and it is not known whether the pattern seen in North America is representative of global dinosaur diversity. then.
Eggs and eggshell fragments represent the last 2 million years of the dinosaurs, with fossils representing every 100,000 year interval. The study involved analyzing more than 5,500 geological samples and applying computer modeling to obtain a detailed estimate of the age of the rock layers.
Analysis found the whole Eggs and eggshell pieces Only three species of dinosaurs, the researchers said, suggest low dinosaur biodiversity during this time.
Macroolithus yaotunensis and Elongatoolithus elongatus belonged to a group of toothless dinosaurs known as oviraptors, while a third, Stromatoolithus pinglingensis, was A plant-eating hadrosaur, or member of the duck-billed dinosaur group.
The researchers They said their findings from the fossilized eggs are consistent with dinosaur bones found in the same and surrounding area, although they have discovered a few additional dinosaur bones from the region that show that. Tyrannosaurs and sauropods also lived in the area between 66.4 million and 68.2 million years ago.
“Our results support a long-term decline in global dinosaur biodiversity around 66 million years ago,” the study said, “which likely set the stage for the Cretaceous nannovian dinosaur mass extinction.”
Most of the dinosaurs went extinct, but Some survived as small, bird-like creatures and evolved into the birds we see today.
“These findings also contrast with the diversity of egg remains found in places like Spain and the diversity of bones, teeth and other remains we know based on the North American record,” he said by email. “So I believe these authors are misinterpreting these signals.”
He believes an asteroid strike was the real driver. Extinction of the dinosaurs
“Dinosaurs were probably fine and diverse and if it hadn’t been for the last time, Cretaceous asteroids (they) might still be dominant today as far as we know.”