ornithischian classification (modified; more detailed)

["Ken Kinman" <kinman@hotmail.com>]

Dear All,
    Okay, here is my modified and expanded classification (with more 
plesions/plesia---anyone know for sure which is correct?).  To avoid 
confusion I will cladistically split the euornithopod clade.  It will also 
avoid a possible priority issue with Iguanodontidae (but I am still fighting 
off the strong urge to lump some of these).
     I am going to remain conservative (for the time being) on the issues 
which George has brought up:
(1) Pisanosauridae (a possible marginocephalian??); and (2) possible 
paraphyly of Thyreophora sensu lato----i.e. Stegosauridae forming a clade 
between an ankylosaurid clade 3A-C (Thyreophora sensu stricto) and the 
ceropodan clade [presently coded 4+].   Look forward to hearing more from 
George ("in due time").  If George is right, I'm not sure if Emausaurus will 
group with the stegosaurs or the ankylosaur clade.  Also wondering if 
Jeholosaurus and Echinodon are part of this thyreophoran mess or if one or 
both of them split off just basal to it (so I didn't put  those two in yet).
     Decided to keep the main clade coding in a vertical column, but 
indented the subsidiary clades like Jaime did.  Does this make it more 
cladogram-like and easier to read?  I might even indent the main clades too 
if it is useful (without getting confusing).
     Hey look, only one paraphyletic family (Protoceratopsidae) in the 
whole bunch now.  More notes below the classification.
           ----Interesting stuff,    Ken Kinman
--------------------------------------------------------
ORDER ORNITHISCHIFORMES
   1   Pisanosauridae
   2   Lesothosauridae (= Fabrosauridae)
   3   Plesion _Scutellosaurus_
    B   Pl. _Scelidosaurus_
     C   Ankylosauridae
      D   Pl. _Emausaurus_
       E   Stegosauridae (incl. Huayangosaurus)
   4   Thescelosauridae (not near ornithopods??)
   5   Plesion _Agilisaurus_
   6   Heterodontosauridae
    B   Pl. _Stenopelix_
     C   Pachycephalosauridae
      ?   Pl. _Chaoyangsaurus_ (incertae sedis)
       D   Psittacosauridae
        E   Protoceratopsidae
         _a_  Ceratopsidae
   7   Zephyrosauridae
    B   Othielliidae
   8   Hypsilophodontidae
   9   Pl. _Tenontosaurus_
    B   Pl. _Rhabdodon_
  10   Pl. _Gasparinisaura_
  11   Dryosauridae
  12   Camptosauridae
  13   Iguanodontidae
  14   Pl. _Probactrosaurus_
  15   Hadrosauridae
---------------------------------------------------------
NOTES:  Not sure why Jaime has Thescelosauridae splitting off before the 
marginocephalians (clade 6), but I'm willing to give this topology a try.  
But I must admit it makes me a little uneasy.
     I noticed Jaime places Plesion Chaoyangsaurus more basally in 
marginocephalians (presumably next to Stenopelix).  Any chance Stenopelix 
and Chaoyangsaurus are sister groups?  You usually see the latter placed 
closer to Protoceratopsids.
     And to answer Jaime's question about family vs. plesion status.  That 
is a compromise I make with PT taxonomists (many who don't like monotypic 
families).  A plesion is a convenient way to classify "problematic" genera 
that may or may not eventually be recognized as separate families.  By the 
way, has anyone proposed a family "Tenontosauridae" (which would probably 
include Rhabdodon?).
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