Gary Nelson says ???There is no such thing as a reptile,??? and I think the point he is making when he says it is a good one: ???reptiles??? are paraphyletic w.r.t birds, and the last common ancestor of squamates and crocodilians (or of either of them and turtles) lived a long time ago: calling them all reptiles suggests that they share traits, and ??? given the number of generations since the com