Re: Shell-Shocked

["Larry Febo" <larryf@capital.net>]

1/6/2000 Rob Meyerson wrote:


>I have a two part question about the evolution of hard shelled eggs.  Now,
we have crocodilians on one end (who I will use as the primitive condition)
and modern birds on the other.  Where, in between these two, did
hard-shelled eggs evolve?  The Mongolia expeditions have uncovered many
ornithischian eggs that appear to have had hard shells, so the transition
may have happened early.
>
>Is it possible that, by developing hard-shelled eggs, the protodinosaurs
gained the advantage they needed to dominate the planet (a hard shelled egg
is harder for a nest robber)?
>
>Comments?



A possible glitch to this scheme would be that crocodilians might have been
(at one time) warmblooded, and therefor may have more actively incubated
their eggs, hence may have had hard shelled eggs to prevent their being
crushed.