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Re: Faunal list (Was Re: Selective Extinction)
Jonathon Woolf wrote:
> Chris Campbell wrote:
> > Jonathon Woolf wrote:
> > <Snip>
> > > And one more factor that needs to be considered: in the Permian,
> > > Triassic, and Cretaceous extinctions, among land vertebrates there was a
> > > metabolic pattern to the survivors. 100% ectotherms like lizards and
> > > crocs survived, though greatly diminished. Highly endothermic animals
> > > like mammals and birds survived, again with heavy losses. Animals with
> > > in-between metabolisms, like dinosaurs and dicynodont therapsids, got
> > > the chop. Again, that seems to be consistent with some sort of massive
> > > climatic disruption. Not a disruption of food supply -- endotherms need
> > > more food than ectotherms -- but to something else. And it had to be
> > > global in its effects, because the extinctions are global.
> > One small point here (well, a rather large one, actually): who says the
> > extinctions were global? We always hear that and say it, but as Donald
> > Archibald points out in his article on the subject in the Padian/Currie
> > encyclopedia we don't know that. He mentions that out of 26 KT sites
> > around the world some 26 are from the Western Interior of North
> > America. That's a really bad sample there; in fact, I'd say that and
> > conclusions dealing with any sort of simultaneous extinction event are
> > pretty suspect based on the lack of data globally. We don't know
> > extinctions were global or simulatneous, and this seems to be one of the
> > most common errors made in extinction theories.
> Maybe the majority of _land vertebrate_ sites are Western North America,
> but it's by no means true that all K-T sites are WNA.
That was a typo on my part; it should have read that 20 out of 26 sites
are in WNA.
> There are known
> K-T strata in India -- the Deccan Traps. There are known K-T strata in
> Mongolia -- Keith Rigby claimed Paleocene dinosaurs from Mongolia a few
> years ago. There are plenty of marine K-T strata all along the Western
> European coast -- Peter Ward has studied extinction patterns in
> ammonites extensively in those European marine beds. There's even some
> good K-T strata in upland Italy -- remember that Alvarez first found the
> famous iridium anomaly in clay samples from near Gubbio, Italy.
Right, but we need to look at consistency. We can't say dinos went
extinct globally at the same time if we don't have KT sites with
terrestrial verts around the globe. Marine sites don't count unless
you're looking at marine critters.
> > > Matter a'fact, it occurs to me that some sort of "reverse El Nino," a
> > > massive cooling of tropical waters, could have precisely those sorts of
> > > effects.
> > And, interestingly, this is entirely consistent with the regression
> > theory and entirely inconsistent with the impact theory (which would
> > presumably result in boiled/superheated waters). It also accounts for
> > the froggies and sharks, who are the real buggers for the impact
> > theory.
> Which is one reason I have strong doubts about the
> apocalyptic-asteroid-impact theory.
Same here. Dinos got nailed by a siege, not one little gun.