From: chris brochu <cbrochu@fmnh.org>
Reply-To: cbrochu@fmnh.org
To: dinosaur@usc.edu
Subject: RE: crocodile reversed or normal
Date: Thu, 24 Aug 2000 07:53:55 -0600
>Ken Kinman wrote:
>
><And everyone agrees that Family Ornithosuchidae is a
>member of clade Archosauria, but the confusion has
>been in which archosaur subclade it belongs. In the
>1980's it was placed in the subclade Ornithosuchia,
>and there was no confusion. But in the 1990's, Sereno
>discovered that it really belongs in Pseudosuchia.
>Unfortunately Ornithosuchia was not cladistically
>anchored on genus _Ornithosuchus_, so cladists have
>the confusing situation of Family Ornithosuchidae
>placed in Pseudosuchia instead of Ornithosuchia. This
>used to confuse me, it seems to have confused you, and
>it will continue to confuse others until the cladists
>get their PT taxonomy straightened out...>
It should be pointed out that in the draft PhyloCode (article 11, I think),
this kind of situation will not arise - if one uses a member taxon's name
as the root for a clade name, that member taxon must also be the specifier.
The importance of doing this wasn't appreciated early in the history of
phylogenetic nomenclature.
chris