Re: Dinosaur Taxonomy

[Dinogeorge@aol.com]

In a message dated 96-01-17 21:37:47 EST, swf@ElSegundoCA.ATTGIS.COM (Stan
Friesen) writes (concerning paraphyletic taxa):

>Which I do.  And so does George Olshevsky (though he tends to use
>them less than I do).

Right. We should use parataxa sparingly, mainly when the number of
evolutionary novelties within the daughter clade becomes large enough that it
is ridiculous to retain the daughter clade within the parent clade. Then you
pick a place to draw the line, and (voila!) you draw it.

>In fact the way I define Herrerasauria it probably includes basal
>Dinosauria! [more or less: small to mid-sized carnivorous dinosaurs
>with four functional toes].

There must be more to Herrerasauria than this. Lagosuchians would fall into
your Herrerasauria, for example (which is actually okay with me; they're
pretty close). Also, the putative herrerasaurian _Aliwalia_ was about the
size of _Allosaurus_ (femur around a meter long), so we're not necesarily
just talking small to mid-sized here.