Palaeontology

Were the dinosaurs really in decline before the asteroid struck ?

By T.K. Randall
October 25, 2025 ·  1 comment

Image: AI-generated (Bing AI / Dall-E 3) After dominating the planet for more than 150 million years, the dinosaurs - which were some of the most successful creatures ever to walk the face of the Earth - were completely wiped out by a catastrophic asteroid strike that brought about unimaginable devastation at the end of the Cretaceous some 66 million years ago.

But what had life been like for the dinosaurs prior to the arrival of the asteroid ?

Recent research has suggested that these creatures were already suffering from significant decline even before the space rock hit, but now a new study seems to have cast doubt on this idea.

To learn more, Dr Andrew Flynn and colleagues used radiometric and magnetic dating to date fossils from the San Juan basin to a period just before the extinction event occurred.

This enabled them to identify significant diversity in the number and types of dinosaur species that were roaming the region at that time and thus demonstrating that the dinosaurs appeared to be thriving, not declining."In the north there were lots of horned triceratops and standard duck-billed dinosaurs like edmontosaurus," said study co-author Prof Steve Brusatte of the University of Edinburgh.

"But in the south there were duck-bills with elaborate crests and, most striking of all, there were enormous long-necked sauropods."

"There is no sign that these dinosaurs were in any trouble, or that anything unusual was happening to them, or that they were in any type of long-term decline."

According to Dr Flynn, the idea that the dinosaurs had been in decline may have been down to the fact that there are fewer exposed rocks - and hence fewer fossils - available to study from this period.

"It looks like, as far as we can tell, there's no reason they should have gone extinct except for [the] asteroid impact," he said.

Source: The Guardian | Comments (1)

Tags: Dinosaurs