Re: Shell-Shocked

[The-Diehl@t-online.de (Thomas Diehl)]

Rob 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.

 Why not? By the way, it seems to me like all archosaurians had (and have) hard 
shelled eggs. Wasn't that a special mark of all reptiles to sort them out from 
amphibians?

> 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)?

 Good idea, but well, look above. But in looking for mammals: Isn't a young 
that 
runs away an even bigger problem for a nest robber?


> ***
> What could possibly go wrong?

 What do I know?

 So long,
 Tom.