::That assumes a cladistic understanding of taxonomy, doesn't it?  By that standard, "reptiles" can't be considered a group without including birds, since crocodiles and birds diverged more recently than crocodiles and turtles.  Mammals might have to be included as well.  While understanding the order of speciation is certainly very important, I'm not sure why this should be assumed to trump the more standard way of classifying animals.  00:12, 13 Mar 2004 (UTC)