May 2, 2025 05:46 PM
https://www.livescience.com/animals/dino...y-suggests
EXCERPTS: Fossil discoveries have long indicated that dinosaurs were shrinking in numbers and diversity prior to the asteroid impact at the end of the Cretaceous period. Previously, some researchers believed this was a sign that dinosaurs were already on the road toward extinction even before the cataclysmic encounter with a space rock. However, this idea has long been controversial, with other researchers arguing that dinosaur diversity was doing just fine at the time of their demise.
"It's been a subject of debate for more than 30 years — were dinosaurs doomed and already on their way out before the asteroid hit?" study lead author Chris Dean, a paleontologist at University College London, said in a statement.
Now, new research published Tuesday (April 8) in the journal Current Biology suggests that the apparent rarity of dinosaurs before their extinction may simply be due to a poor fossil record.
[...] the Maastrichtian may have had poorer geological conditions for fossilization, the researchers suggested. Events such as the retreat of the Western Interior Seaway, which once ran from the Gulf of Mexico up through the Arctic, and the rise of the Rocky Mountains starting around 75 million years ago, may have impeded or disrupted fossilization, making it appear as if there were fewer dinosaurs and less diversity during that time...
[...] "Dinosaurs were probably not inevitably doomed to extinction at the end of the Mesozoic [252 million to 66 million years ago]," study co-author Alfio Alessandro Chiarenza, a paleontologist at University College London, said in a statement. "If it weren't for that asteroid, they might still share this planet with mammals, lizards, and their surviving descendants: birds." (MORE - missing details)
EXCERPTS: Fossil discoveries have long indicated that dinosaurs were shrinking in numbers and diversity prior to the asteroid impact at the end of the Cretaceous period. Previously, some researchers believed this was a sign that dinosaurs were already on the road toward extinction even before the cataclysmic encounter with a space rock. However, this idea has long been controversial, with other researchers arguing that dinosaur diversity was doing just fine at the time of their demise.
"It's been a subject of debate for more than 30 years — were dinosaurs doomed and already on their way out before the asteroid hit?" study lead author Chris Dean, a paleontologist at University College London, said in a statement.
Now, new research published Tuesday (April 8) in the journal Current Biology suggests that the apparent rarity of dinosaurs before their extinction may simply be due to a poor fossil record.
[...] the Maastrichtian may have had poorer geological conditions for fossilization, the researchers suggested. Events such as the retreat of the Western Interior Seaway, which once ran from the Gulf of Mexico up through the Arctic, and the rise of the Rocky Mountains starting around 75 million years ago, may have impeded or disrupted fossilization, making it appear as if there were fewer dinosaurs and less diversity during that time...
[...] "Dinosaurs were probably not inevitably doomed to extinction at the end of the Mesozoic [252 million to 66 million years ago]," study co-author Alfio Alessandro Chiarenza, a paleontologist at University College London, said in a statement. "If it weren't for that asteroid, they might still share this planet with mammals, lizards, and their surviving descendants: birds." (MORE - missing details)