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Dino Eggs and Mammals



Howdy all.  I've been in lurker mode for the past few months, but thought
I'd step back into the fray now.  
I read through John Bois' stealthy-egg-eating-mammals-theory posts and have
some...concerns.

First:  If the mammals did, indeed, become better adapted for egg-eating
near the end of Cretaceous, as John suggests, wouldn't we some sort of
morphological change in mammals around that time, related to such a change?
What are the adaptations for egg-predation, anyway?  

Second:  Mammals would STILL have to compete with the various
non-dinosaurian reptiles for those same eggs.  Is there any evidence to
suggest that the mammals were better at egg-predation than the "old hats" were?

Third:  I seriously doubt that mammals would eat the dinos into extinction
(even if the latter were in a decline), simply because it doesn't make good
ecological sense to do so.  If you eat all of your primary food source, you
starve.  

Fourth:  Since the dinos' habitats ranged world-wide, and I trust, the
mammals' as well, it seems rather odd that all dinos everywhere would
succumb to the mammal sneakiness at the same "time".  I realize that John is
not proposing a one-fell-swoop kind of thing, but surely there would be an
area where there simply were no egg-eating mammals.  These dinos, then
should have survived.

Fifth:  While mammals may have been getting smarter, so were dinos, I am
sure.  Unfortunately, we'll really never know how smart either group really
was at the time.

Sixth:  Egg-eaters or no, I still think that something very real occurred at
the K/T boundary, and it killed more than just the non-avian dinosaurs.
Whether it be a bolide, vulcanism, alien invasion, or a combination,
something definitely happened.  The big sea-reptiles all vanished.  Plankton
took a heavy beating.  Ammonites.  Trilobites.  Gone.  Mammals were not
responsible for their demise(s).

Seventh:  While the dinosaurs in general were probably not burrowers, that
wouldn't necessarily prohibit some of the smaller ones from capitalizing on
any burrows that happened to be handy.  Crocodiles, while not burrowers
themselves (at least not that I know of), do hide out in burrows during
droughts.

Eighth:  While I'm not entirely sure about this point, it seems to me that a
large portion of the dinosaur eggs found are intact.  Meaning, of course,
they were not preyed upon.  Is this the case for Cretaceous eggs?  

Ninth:  The herding dinosaurs would have been better protected, not simply
against large-scale predation by T. rex et al., but against the little guys,
too, I would think.  If there's a greater chance of being noticed, there's a
greater chance of being stepped on by an irate mother when you come to steal
an egg or two.  Yet, they, too, are gone.

None of this is to suggest that dinosaur egg predation didn't occur, perhaps
even extensively, near the end of the Cretaceous.  I'm just not sure that it
would have caused the demise of all known species of dinosaur living at the
time.
All in all, it seems to me that any effect the mammals might have had with
respect to the demise of the dinos would have been solely behavioral.
Behaviors, insubstantial as they are, don't fossilize well.  So, my question
is this:  is there any PHYSICAL evidence to suggest that dino eggs were
being preyed upon extensively near the end of the Cretaceous?  Things like
egg fragments (which would, of course, have to be indistinguishable from a
normal hatching), fossils of trampled mammals with their jaws wrapped around
an egg, anything of that sort?

Anyway, enough rambling.  
Derek Smith
DSmith0531@AOL.com
djsmith@ccnet.com