What are mesosaurs? I have Laurin and Reisz 1995. It's not much help in nailing down this taxon. I haven't seen Sean Modesto's work (please send pdfs if possible!) and his email address seanmodesto@uccb.ca bounces back undeliverable. Why can't mesosaurs be a basal sauropterygians, perhaps close to Lariosaurus? Really curious. David Peters St. Louis