Thank-you to everybody for the clarifications. (I'm halfway through the article by Benton at the moment, especially liking it's thoroughness).
>For one thing, certain traditionally paraphyletic groups, converted to >clades, would contain other taxa of equal or even greater rank. Ordo >Saurischia, for example, would include Classis Aves. You could reassign >ranks, but would find very soon that you had run out of space.Has the idea of setting points along phylogenies where the ranks are "reset" been discussed?