So It Wasn't Hunters With Stone Tools

Picture Credit: Everything Dinosaur

There's a school of thought -- if you want to call it that -- out there that credits human being with all the extinctions throughout prehistory, particularly the North American megafauna at the onset of the latest interglacial period. I've pointed out time and time again that, in most cases, the populations concerned were already under stress from environmental changes (as in the onset of the interglacial). Well, that seems to have been the case with the dinosaurs:

Sixty-five million years ago, a massive asteroid slammed into Earth, causing tsunamis, earthquakes, fires, a global winter and the end of the age of the dinosaurs.

But what if the asteroid had glided safely past our planet? Would dinosaurs still be here today?

New research suggests the answer is probably not. Instead, scientists have found evidence that dinosaurs were in the midst of a long, slow decline that began millions of years before the asteroid struck. . . .

The authors are not sure what caused the speciation rate to slow down, but they have a few ideas. They explain that the Cretaceous period (145.5 million to 65.5 million years ago) was a time of drastic geological changes. The global climate was cooling down, there was prolonged volcanic activity and the continents were breaking apart.

Like I keep saying, environmental changes will do it every time.