Extinction of Dinosaurs: Consensus Reached . . . mostly

I think the paper does link the K-T (aka K-Pg in the paper) conclusively with the Chicxulub impact and provide good reason to think volcanism and multiple impact scenarios fail to explain the spread of evidence.But there's still no explaination as to why the Chicxulub impact wiped out the non-avian dinosaurs, specifically, whilst leaving the crocodilians, birds and mammals. Similarly for the various other groups that survived or went extinct.The paper also, bizarely, claims that "[t]he scale of biological turnover between the Cretaceous and Paleogene is nearly unprecedented in Earth history". And supports it with a reference neatly detailing the other mass extinctions... umm? And that's the real problem I have with impact explainations for the extinction of the dinosaurs - there is no evidence of impacts that co-incide with prior mass extinctions. It seems to me that the search for abiotic explainations of mass extinctions is missing the big picture: extinction seems to be a property of evolutionary systems.Chicxulub happened, it explains the geological features of the K-T boundary. But it cannot be considered an answer to dinosaur extinction question until it can explain the distribution of survivors.

Maybe, but it certainly should be able to explain what it's trying to explain - in this case why the dinosaurs died out. The impact isn't an answer to that question because it doesn't explain why other groups didn't die out and thus leaves the question unanswered. It is simply not possible to find clear dividing lines like that between groups which survived and groups which didn't. While the popular face of dinosaurs might be the big beasts, there was a whole diversity of different dinosaurs out there, from tiny omnivores to massive sauropods. A fact that becomes increasingly pertinent as it becomes increasingly clear how similar the smaller theropods were to birds.

It invalidates it as an explaination, because it's not explained it. Suppose you ask me how I got to be a Games Programmer and I reply "I went to school" - it'd be true, to a point, without all that schooling I wouldn't have the skills I need but it doesn't really answer the question but it doesn't address why I'm a Games Programmer and everyone else who went to school isn't.The impact is not an explaination because it doesn't explain the survival patterns. True, but then we're just left asking why did no non-avian dinosaurs make it through in that noise?

Good analogy, let me think on that.I'd say whether tornado theory provides an answer would depend on the question - it seems to me the question of the K-T extinction event is why did the dinosaurs die out when all these other things didn't. A question which is equivalent to asking why your friends house survived when the others didn't. A question which cannot be answered simply by saying there was a tornado.

Hmm... aren't the "major" mamalian clades defined by their existence post K-T, so - by definition - survived? As I understand it the fossil record of most mammalian clades are pretty scarce pre K-T anyway, and we only know they diverged prior to it because of genetic studies using molecular clocks.

Ah, those major mammalian clades.Yes, quite right. I was thinking more around the 'Order' level.