Re: Polacanths and sauropods

["Jaime A. Headden" <qilongia@yahoo.com>]

Nick Pharris wrote:

<Random comment--I still say _Minmi_ should get its own family.>

  Since the group would have only one genus, it would be redundant:
the familial, generic, and specific diagnoses would all be identical.
Why a family, when a genus would do? Monotypic families or other
suprageneric taxa, I think, are going out of fashion. Hence
<Ingeniidae>, <Ingeniinae>, <Alxasauridae>, <Blikanasauridae>,
<Massospondylidae>, <Yunnanosauridae>, and some others are all so
redundant, they have no taxonomic value. Mark that this practice was
without wide acceptance of phylogentics as currently practiced, but
rather of Linnean taxonomy: there had to be a "family" for every
genus, and if that genus does not compare to other families well
enough, then there would be a new family made, to "differentiate" the
genus. *Minmi* presently occupies a position that does not make room
for another genus more similar to it than to another "family", so it
must remain separate, along with *Scuttellosaurus* at the base of
Thyreophora.

___!Thyreophora!
 \_*Scuttellosaurus*
  \_*Scelidosaurus*
   \_*Emausaurus*
    \___!Eurypoda!
      \___!Ankylosauria!
       \ \_*Minmi*
        \ \_Nodosauridae
         \ \_Polacanthidae
          \ \_Ankylosauridae
           \__!Stegosauria!
             \_Huayangosauridae
              \_*Dacentrurus*
               \_Stegosauridae

  I think this is the current accepted model? Minmi is merely the
outgroup to all other ankylosaurians, and if there was to be a new
named node, it would be <all other ankylosaurians and not *Minmi*>.
Sereno, 1986, I think discussed all this, but I'm not sure, as I
haven't read this, so I'm just flapping in the breeze. (Ornithschians
are not my strong suit. Well, neither are theropods, but that hasn't
stopped me yet!)



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