The dinosaurs’ gradual decline

Uh-oh. And the uh-oh is for: 'in the fifth mass extinction.' I think we need to think about that more.... there have been five mass extinctions in the past *that we know about.* Why are we so arrogant to think we aren't going to fall to the same fate? I guess there are scientists out there who know this is a matter of when not if... but this is not a discussion at any gatherings I attend.

We talked about previous elimination of competition here, with the 'hobbits'. And we know we are doing a great job wiping out frogs and other amphibians... so, we are helping this demise along, thank you very much.

Paleontologists have long argued over exactly what annihilated the dinosaurs 66 million years ago, though most agree it was some immense catastrophe, most likely an asteroid smashing into Mexico’s Yucatán Peninsula, massive volcanic eruptions, or both. Recent research, however, puts a new twist in this prehistoric scenario, suggesting that dinosaurs were experiencing a slow decline long before cataclysmic events finished them off for good. When Nyasasaurus and the other early dinosaurs first appeared, more than 230 million years ago, they quickly evolved into new species, filling a wide range of ecological niches. But an analysis of three large dinosaur family trees reveals that most of these groups were dying off faster than new species could emerge to replace them. This decline began unfolding some 50 million years before dinosaurs were ultimately wiped out, in the fifth mass extinction that marked the end of the Cretaceous period, reports The Washington Post. With fewer species and less variation in habitats, paleontologists speculate, dinosaurs became more vulnerable to changes in their environment, making their demise inevitable. “While the asteroid impact is still the prime candidate for the dinosaurs’ final disappearance,” says study author Manabu Sakamoto of Britain’s University of Reading, “it is clear that they were already past their prime in an evolutionary sense.”

Article taken from the May 6th edition of The Week Magazine.