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Re: Nitpicky cladistics



        Erratum to previous post (I'm getting a headache from this...)
At 02:04 PM 11/17/96 -0600, I wrote:

>        Just for the sake of example, if Ornithosuchia are more closely
>related to crocodiles than to birds, Maniraptora {+ Aves, - Ornithomimus}
>will be the sister group of the "ornithodirans"
(Dinosauria, Pterosauria, etc)
>which suddenly becomes... drumroll please, the Arctometarsali!

        In retrospect, this is almost assuredly incorrect.  Ornithiscia {+
_Triceratops_/_Iguanodon_, - Aves} probably has priority, although I am not
sure.  Dinosauria {+ Aves, + _Triceratops_} occupies the node formerly
identified as "Archosauria".  If this is the case, the taxonomy becomes:

        Archosauromorpha: (basal "archomorphs", Dinosauria (Maniraptora,
Ornithiscia))
        Maniraptora: (basal animals not part of the {+ Eosuchia, + Aves}
clade, Archosauria {+ Eosuchia, + Aves})
        Archosauria: (Pseudosuchia, Ornithodira [which does not include
dinosaurs, but does include the birds])

        At this point, Crocodiles are dinosaurs, as are pterosaurs, most (if
not all) "thecodonts", and dozens of other critters.
        Wince!

        Wagner


+--------------------------------------------------------------------------+
| Jonathan R. Wagner                    "You can clade if you want to,     |
| Department of Geosciences              You can leave your friends behind |
| Texas Tech University                  Because your friends don't clade  |
| Lubbock, TX 79409                               and if they don't clade, |
|       *** wagner@ttu.edu ***           Then they're no friends of mine." |
|           Web Page:  http://faraday.clas.virginia.edu/~jrw6f             |
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