re: Endothermic Crocs in Nature

[david peters <davidrpeters@earthlink.net>]

Kris,

Opinion follows:

Considering that early crocs are hard to distinguish from early dinos (witness 
Macelognathus, Scleromochlus, etc.), especially when just their bits and pieces 
are known, I could easily buy into endothermy devolving into something less in 
a sit-and-wait predator. As Greg Paul has noted earlier, apparently the easiest 
time for a taxon to revert is when it is only a few steps into the next level. 
Perhaps the same has occurred here as well. 

As an aside, and similarly (perhaps) among primitive chordates, I always 
wondered about the echinoderm > chordate hypothesis when the early chordates 
had the simpler wormlike Bauplan and devolving to sit-and-wait (or 
sit-and-filter) lancelets > echinoderms seems to be a more logical and 
parsimonious degression, regardless of wriggly larvae.

David Peters
St. Louis