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Re: Predators of the non-stealthy egg theory.



On Sun, 21 Apr 1996, Betty Cunningham wrote:
> What about the niches where they were likely direct competitors such
> as egg-eating.  We KNOW dinosaurs ate dinosaur eggs (or we did for
> quite some time, but now we are a bit confused about such things as
> Oviraptor.)  We BELIEVE mammals ate dinosaur eggs.  Isn't this direct
> competition?  The same niche?

O.K.

> Is your arguement for your position or
> against it?

I think for it.  But I'm not sure why this would be important or not.

>  (It was probably a competition that lasted as long as mammals and
> dinosaurs existing together (what, 120 million years?) so would you
> say the extinction was a result of egg-predation over a very long
> period, or was it perhaps something a little more specific to the 60
> million-years-ago mark?)

I think the dinosaur was dependent on a defunct strategy: laying eggs in
the open-field.  Their existence was probably marginal for a long time.
And then the mammals, with their newly evolved "technologies" added to
their egg-predation load.
> Your 7 yr old has evolved 60 million years further than the state of
> mammals at the extinction of the dinosaurs.  So have the crows.
> Perhaps the "technology" of cognitive thought is a little newer than,
> say, the Late Cretaceous.  Where is the evidence to support or deny
> this?  I'd like to see a fossilized thought, please.;]

See response called: competency of mammals.
>
> > Mammal egg layers could be stealthy.  They could put them in
> > burrows.  Look at the platypus.  It burrows _under water_.  Tell
> > me that is not an adaptation for stealth--against egg predation!
>
>  Underwater burrows would still allow access for snakes and crocs, I
> don't see how water-oriented burrows would actually be all that much
> better for the platypus than a ordinary burrow, nor where cognitive
> thought guided the platypus in choosing the same sort of burrow as,
> say, a burrowing owl would. (As I understand it, platypuses are dumb
> as bricks) The platypus is laying it's eggs on a landmass which is
> known for it's impressive fossil record of really really big snakes.

On land you go into a burrow and there is your egg.  A predator can
observe you do it.  Under water you can dive into the water at one spot
and swim up or down stream to your burrow.  Thsi makes it more difficult
to find.  Relative to an open-field egg-layer, your stealthy efforts will
be rewarded.