I don’t ever remember hearing it suggested that dinosaurs were “sliding towards extinction” before the impact event.
I’ve always heard it WAS the impact that caused the extinction.In another life, I attended a large geology conference and went to a session with talks about this. They had two speakers back to back, one boiled down to “it was the asteroid” and the other “it wasn’t the asteroid”.
Not only did the speakers get heated in each other’s question sections, the whole ROOM felt like it was about to get into a fistfight - everyone basically taking over each other to the person to their left, right, front, back. Extremely hostile!
I can’t remember the evidence but I do distinctly remember thinking that it wasn’t my subject matter and I should probably avoid forming an opinion on it for my physical safety in my career.
Now I’m free to offend paleontologists both professionally and unprofessionally and I can’t remember how to :'(
I love this. Thank you for sharing your experience of fiesty geologists.
There were some theories about volcanism and other events that changed the environment enough to cause their decline, but from what I remember, most of those were proposed before we found the Yucatán crater.
Layman here, but as I recall there is a more recent theory that the evolution of flowering plants (130ish MYA) played a role in the decreasing diversity of the huge dinosaurs.
The usual evidence used for that is that the Triceratops like species seem to end up with just the one, and Trex appeared to be the only large predator in its ecosystems.
Although I understand there is new evidence suggesting that the North American Trex specimens found might be at least three different subspecies.
If I remember correctly, those two species were actually separated by millions of years.
Yes, that doesn’t change my point. In both cases it looks like the ecosystem had multiple niches that in the fossil record previously having different species apparently all filled with a single species. With Trex, one of the current theories is that it filled different niches as it grew up.
Although with Trex, there may have been a half sized version that was hunting alongside the big one(s).
This is really cool! The evolution of dinos into birds really fascinates me. Time for a new internet rabbit hole.
