Kathmandu: A new study challenges the long-held debate that dinosaurs were already in decline before a massive asteroid wiped them out 66 million years ago. Researchers say dinosaur populations were still thriving in North America shortly before the extinction event.
The findings, published Thursday in Science, come from fossils unearthed in the Kirtland Formation of northern New Mexico. Scientists determined that these fossils—belonging to species such as Tyrannosaurus rex and a Triceratops-like herbivore—date back to about 400,000 years before the asteroid impact. The team used volcanic glass particles and magnetic minerals in the surrounding rocks to determine the fossils’ age.
“Dinosaurs were quite diverse and now we know there were distinct communities roaming before being abruptly wiped out,” said co-author Daniel Peppe of Baylor University.
The study’s results contrast with earlier claims that dinosaurs were dwindling before the asteroid strike. Differences between the New Mexico fossils and those from the same period in Montana further suggest varied and thriving dinosaur ecosystems across regions.
However, experts caution that the data from one site cannot represent global conditions. “This is very exciting, but it’s just one location,” said University of Bristol paleontologist Mike Benton.
Researchers hope further studies will shed more light on how diverse dinosaur populations were worldwide in their final millennia.
-AP