Study shows dinosaurs were thriving in North America before asteroid strike that caused mass extinction

Scientist There has long been debate over whether the dinosaurs went extinct before the asteroid hit. Earth 66 million years ago, causing a mass extinction.

New research shows dinosaur populations were still thriving North America Independent experts say that preceded the asteroid strike, but this is only a piece of the global picture.

,dinosaur “There were quite a few diverse communities, and we now know that there were quite a few different communities roaming around before they were suddenly destroyed,” said Daniel Peppe, a paleontologist at Baylor University and co-author of the study.

The latest evidence comes from analyzing a portion of the Kirtland Formation in northern new mexico It has been known for many interesting dinosaur fossils for almost 100 years.

Scientists now say those fossils and surrounding rocks date back to about 400,000 years before the asteroid hit, which is thought to be a short interval in geologic time. The age was determined by analyzing small particles of volcanic glass within the sandstone and by studying the direction of magnetic minerals within the mudstone of the rock formation.

The results suggest that “the animals deposited here may have been living near the end of the Cretaceous,” the last dinosaur era, Peppe said.

The findings were published Thursday in the journal Science.

The difference between a dinosaur species found in New Mexico and a dinosaur species found at a site in Montana, previously dated to the same time frame, “contradicts the idea that dinosaurs were in decline,” he said.

Previously found fossils at the New Mexico site include Tyrannosaurus rex, a huge, long-necked dinosaur, and Triceratops, a horned herbivore.

Scientists who were not involved in the study cautioned that evidence from one location may not point to broader trends.

“This new evidence about these very late-lived dinosaurs in New Mexico is very exciting,” said paleontologist Mike Benton of the University of Bristol, who was not involved in the study. But he added, “This is just one location, not representative of the complexity of the dinosaur fauna of that time in all of North America or the world.”

Although scientists have found dinosaur fossils on every continent, accurately dating them can be a challenge, said Andrew Flynn, a paleontologist at New Mexico State University and co-author of the study. Easily datable materials like carbon do not survive in fossils, so scientists must look for nearby rocks with precise characteristics that can be used to determine the age.

Further research could help complete the picture of what types of dinosaur species were alive globally on the eve of the asteroid crash, Flynn said.

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