My question is: How do we "know" where they lived within the water collum?
I know all paleontological theories are based off of scant evidence and some are pure conjecture, but I am wondering if there is "special" evidence for these fossils that can distinguish the swimmers from the bottom dwellers?
Ask and Ye shall receive!! Thanks for the detailed answer Phil.
spartacus said:Archy, as you're obviousy an info Hoover ...