Re: Subterranean K-T strategies (was "I know why...")

["Scott P. Smith" <scott@scott-smith.com>]

I'll buy that.  I have never heard an adequate explanation of why ALL
species of dinosaurs died, while some birds and reptiles survived.  The
buried egg theory seems a plausible explanation.

I don't buy the small size argument though since there were plenty of small
dinosaurs.  Seems implausible that all small dinosaurs would die if size was
a significant factor in surviving the K-T.

Scott

----- Original Message -----
From: "Ken Kinman" <kinman@hotmail.com>
To: <dinosaur@usc.edu>
Sent: Wednesday, July 18, 2001 4:19 PM
Subject: Subterranean K-T strategies (was "I know why...")


>
> Scott,
>      I disagree with the 24/7 caring mother idea, and not just because
> oviraptorids didn't survive.  Any bird or dinosaur sitting on a nest on
the
> ground or in a tree was probably doomed (along with its eggs) no matter
how
> devoted a parent it was.
>       A more effective strategy was living underground (the same way most
> mammals survived).  Having a nest in a subterranean burrow would have been
a
> much better idea, or better yet a freshly inseminated female surviving in
> such a burrow and laying her eggs later in the protection of said burrow.
>       Or a variant on that "Subterreanean strategy" may have been shared
by
> crocodiles and some birds (burial of eggs, as you mentioned).  Freshly
> buried eggs in a mound of alkaline soil (which would help neutralize acid
> rain).  Even if all the parents are killed off in the disaster, some
> surviving eggs could hatch into precocious chicks, and a few lucky species
> managed to squeak through the extinction.
>       Offhand I don't which of these underground strategies would have
been
> better, but either would be far better than an exposed parent above the
> surface of the ground:  they would have been "sitting ducks" or "sitting
> oviraptors" (bad pun, but obviously intended).  :-)
>       Whatever survived underground could try to make a living coming out
to
> scavenge, eat insects, seeds, or whatever (or underground insects, seeds,
> tubers).  Underground was the place to be for land dwellers, and of course
> living in water was an even better alternative (except for the
phytoplankton
> and animals which were dependent on phytoplankton for food at some stage
in
> the life cycle, such as those poor ammonites).
>      No single, simple answers to K-T survival, but there seem to be
trends
> such as those discussed above.  Also being small (and not requiring lots
of
> food) helped, and of course being an Australian or Antarctic form was a
> piece of luck that would have given one a distinct advantage over those in
> North America.  Anyway, those birds which did survive the extinction (less
> than a dozen species?) were probably mostly southern and liked to dig
holes.
>   Those are my thoughts.
>                     --------Ken Kinman
> ********************************************************
> >From: "Scott P. Smith" <scott@scott-smith.com>
> >Reply-To: scott@scott-smith.com
> >To: <dinosaur@usc.edu>
> >Subject: I know why birds and some reptiles survived mass extiction
> >Date: Wed, 18 Jul 2001 10:34:32 -0400
> >
> >OK, now that I've got your attention...
> >
> >Sorry if this has already been discussed, but it seems to me that the
> >determining factor as to why all non-avian dinosaurs died while avian
> >dinosaurs survived is the degree to which they cared for their eggs.  I
> >believe that species that protected their eggs from the elements by
either
> >burying them or constantly sitting on the nest are the ones that survived
> >the extreme climatic changes at the K-T boundary.  Simple explanation to
> >explain why we have no non-avian dinos today.  Maybe only a few (or one)
> >species of avian dinosaur sat on its nest 24/7 and gave rise to all the
> >varieties we see today.
> >
> >
> >Thought?
> >
> >
> >Scott
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