Last night I wrote: > Hopson discusses two > definitions of Mammalia: the "classic" definition where a mammal is defined as > anyhing that has all the features considered to be diagnostic of Mammalia; and > Rowe's phylogenetic definition of Mammalia as a stem-based taxon (thx for the > correct term) composed of the LCA of Theria and Monotremata, and all > descendants of > that ancestor. Gotta stop writing messages so late at night . . . of course, Rowe was using a _crown_ based definition there. My mistake. -- Jon W.