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Word from the sole "non-stealthy egg" believer.
On Thu, 14 Nov 1996, Mickey P. Rowe wrote:
John Bois wrote:
> > For argument's sake, assuming for a moment this is what
> > happened, the ultimate cause of dino extinction, since only they
> > became extinct, is the non-stealthy egg!
> John, so far as I know, you're the only person in the entire world who
> accepts (apparently without question) that dinosaurs were
> "non-stealthy" egg layers. Why would the smaller dinosaurs be any
> less stealthy than the crocodilians which were missed by your "smart"
Crocodiles were niche sovereigns. They remain so today. Would-be egg
thieves are loathe to enter their domain because the crocodiles enjoy
such an advantage in their swampy medium. Also, while some guard their
nests, others lay and forget. This may not have been a luxury afforded
to eggs which required attention--in other words, if dinos were
endothermic they must tend their nest. In any case, there is plenty of
evidence of dino parental investment. This requires many non-stealthy,
predator-alerting trips to and from the nest!
Over the Cretaceous, dinosaurs tended to get bigger. The bigger
you are the harder to hide. Something, maybe basic dinosaur constraints,
limited their competitive ability in the small animal niche. As the
Cretaceous wore on, smart, super-stealthy, and reproductively-secure
mammals may well have made life impossible for big animals seeking
protection in close cover. What is left? Set up an egg mountain. Lay
your eggs in some scrubby terrain where not many small things can
travel. Move to the highlands. Create egg-protecting societies.
Dinosaurs were increasingly forced to develope strategies of defence
rather than strategies of stealth. This was expensive. How much better
to carry your babies away (like mammals), or to hide your eggs in
out-of-the-way-places such as offshore islands, inaccesible locations
(like birds and snakes), or to lay and forget (like turtles). Dinosaurs
made a tremendous gambit for the open-field, big animal niche. And for
a while (a long while) they were successful. But their life style had a
fatal flaw: while their body architecture was fit, their reproductive mode
was not. Too bad they don't award partial credit in evolutionary stakes.