[Strategerist]

Actually it appears the site you cite, and a handful of others, are flat out wrong or confused.

Certainly the more recent cites and articles and the more fully explained articles, and by far the majority, attribute the Permian extinction to warming, not cooling.

I wonder if some sites are confusing the Permian extinction and the "Snowball Earth" hundreds of millions of years earlier.

[Deek]

Certainly the more recent cites and articles and the more fully explained articles, and by far the majority, attribute the Permian extinction to warming, not cooling.

Everything I have seen recently points to an earth-impact in what is now Australia. Based on the volume and distribution of the shocked quartz, it may be larger than the Yucatan collision.

[George - the Other]

"Actually it appears the site you cite, and a handful of others, are flat out wrong or confused."

Hardly confused.

Scientists are always debating about the evidence they find. For example, while the asteroid impact theory about the demise of dinosaurs is the one favored today, there are still well trained experts in the field who disagree.

Another big area of disagreement is the origin of birds. While all paleontologists agree that they are descended from archeosaurs, some feel they are really dinosaurs, while others feel they come from a closely related but distinctly separate line of reptiles.

Even with all the research and new discoveries and new ways of interpreting data, we might never know for sure.