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Hadrosaurs [was re:(no subject)]



        Pete wrote:

>Conversely, perhaps your contention is based on the fact that most other 
>dinosaurs are generically oversplit.
        I find it a good idea to view such questions in terms of
well-established, polyspecific genera. Ask yourself: can this "genus" be
accomodated (phylogenetically) within another, if the other is more broadly
concieved. For example, most chasmosaurines ceratopsians can be accomodates
with Chasmosaurus itself (unless you believe the latter to be polyspecific).
On the other hand, many theropods have poorly resolved relationships, as do
many early iguanodonts. There is simply no other genus within which to fit
Ouranosaurus, or Ornitholestes, etc.


>Take hadrosaurids for example: do 
>Anatotitan and Edmontosaurus really need to be in different genera? 
        Sadly, probably not. Too bad, too, Anatotitan is a COOL name! But,
it is very very very likely that these two "genera" are at least sister
groups (more likely the former is within the clade of the latter), and thus
it is hard for me (as an avowed enemy of the monotypic taxon) to retain the
distinction.

>Do Hypacrosaurus, Corythosaurus and Lambeosaurus need to be in different 
>genera?  Probably not for both questions.
        Actually, there are structural characteristics which suggest that
Lambeosaurus should be maintained for the time being. I am unconvinced that
Corythosaurus is warranted, but there are hints that Hypacrosaurus may be
exclusively associated most closely with a different "genus" of
lambeosaurine. I am not saying anything. I didn't say anything then, and I
am not saying anything now.

        Wagner
--------------------------------------------------------------------------------
     Jonathan R. Wagner, Dept. of Geosciences, TTU, Lubbock, TX 79409-1053
  "Why do I sense we've picked up another pathetic lifeform?" - Obi-Wan Kenobi