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

["João S. Lopes Filho" <jodan99@uol.com.br>]

I'm also not convinced by the current theories of K-T extinctions. Many
groups were killed: dinosaurs, pterosaurs, sea reptiles (with the exception
of turtles), non-Neornithes birds, many kinds of non-Therian and Therian
mammals, but another groups were saved: snakes, lizards, frogs, crocodiles,
placentals, marsupials, etc
----- Original Message -----
From: Scott P. Smith <scott@scott-smith.com>
To: <dinosaur@usc.edu>
Sent: Wednesday, July 18, 2001 1:39 PM
Subject: Re: Subterranean K-T strategies (was "I know why...")


> 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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> >
> >
>