Re: Egg-types and Taxonomy?

[Stang1996@aol.com]

Thomas_R_HOLTZ@umail.umd.edu
<<If the D.S. egg was the primitive dinosaur condition, the ornithoid a
derived theropod condition, and the D.P. a derived cerapod 
(ornithopod + marginocephalian) condition, you would get the pattern 
seen above.  After all, for every character, there is a primitive state.  
Anyone know what is the condition in dinosaur outgroups?>>

The D.-P. eggs are only found a few ornithopods though, most of 
them have D.-S. eggs.  My point was though, that in the 
monophyletic saurischia arrangement one would expect more 
similarities (some similarities) between sauropods and theropods' 
eggs; rather than between sauropods and ornithischians' eggs.  In 
other words: why would a group have more in common with its 
outgroup rather than its sister taxon?  I'm not sure about any 
thecodont or pterosaur eggs being found; on the same page they 
showed croc egg structure for comparison though.

Peter Buchholz
Stang1996@aol.com