K-T survivors (hadrosaurs?, mammals & birds)

["Ken Kinman" <kinman@hotmail.com>]

    The overall evidence does indeed seem to show that the Northern 
Hemisphere got the worst of it, even though there was still severe 
devastation in the south.  The acid rain was probably much worse up here 
(including downwind Eurasia), which would kill off a lot of the survivors of 
the initial devastation.  That would include plant survivors, so starvation 
would have been even worse up here for any herbivore survivors.
     However, next month the newest evidence is scheduled to be published 
on the possibility of hadrosaurs surviving into the initial million years of 
the Paleocene (at least in south-central North America).  And as Fassett has 
suggested, hadrosaurs would have most likely survived as eggs buried 
underground.  If such nests were well-drained or in alkaline soil, the acid 
rain problem would be diminished.  The eggs would have hatched many months 
(perhaps even over a year) later.  This may have perhaps occurred as the 
"fern spike" was beginning, and hadrosaurs would have had it good for a 
while (at least until bad times returned, such as an exploding mammal 
diversity starting to compete for food or consuming hadrosaur babies and 
eggs).  Anyway if Jim's new evidence is convincing, I still think it could 
be one of the biggest paleo stories of 2002 (maybe ornithischians will 
upstage saurischians for a change).  I'll check with Fassett to see if 
publication is still on schedule.  I can hardly wait to read it.
     I would quibble a little bit that "most modern mammalian groups are 
Gondwanan".  Mammals up north (the boreoeutherians) exploded in diversity in 
the early Paleozoic into many ungulate groups (incl. whales), and bats, 
rodents, lagomorphs, primates, carnivores (i.e., the vast majority of 
today's mammal diversity at the level of species, genera, families, and even 
orders).  Those groups then invaded the Southern Hemisphere and largely 
outcompeted the old placental mammal groups (like elephants, aardvarks, 
manatees, xenarthrans, and a few old insectivore relict groups).  In my 
opinion, it is very similar to what apparently happened to birds (especially 
the relict paleognaths).
            ------   Ken
******************************************
Dan Bensen wrote:
> Wow!  If most modern mammalian groups are Gondwanan, and most (or all) 
> modern _birds_ are also Gondwanan (see article in recent, one begins to 
> wonder whether the Chixulab left much alive in the Northern hemisphere at 
> all.



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