[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: preliminary ornithischian classification

<I went ahead and put in a plesion for Thescelosaurus below as

  Why not Gilmore's Thescelosauridae, possibly including
Bugenasaura as well?
<By the way, are there any major objections to placing Iguanodon
as a primitive hadrosauridae?>

  Yeah, the possible paraphyletic arrangement of Hadrosauridae,
based on a relatively minority analysis primarily stemming from
teeth by Horner, 1990, which finds hadrosaurines and
lambeosaurines deeply split. But, since only one analysis in the
history of hadrosaurid analyses and not once backed up by a
subsequent analysis in which time itself has had plenty of
opportunity for, it would seem best to ignore this for now :)

<I didn't see any need to maintain that as a small family of its
own (but I have this dreadful feeling someone is going to tell 
me Iguanodontidae has priority).>

  What, small families as sister groups are bad? Why not
traditional Hypsilophodontidae, paraphyletic, but certainly
giving rise (paraphyletically) to dryomorphs....


I would suggest the following arrangement:

>   ORDER ORNITHISCHIFORMES (ornithischians; predentates)
>         1  Pisanosaurus
>          2  Lesothosaurus
>           3A Scutellosaurus
>             B Scelidosaurus
>              Ca  Minmi
>                b  Nodosauridae
>                 c  Gastonia
>                  d  Shamosaurus
>                   e  Ankylosaurus
>              Da  Huayangsaurus
>                c  Dacentrurus
>                 d  Stegosaurus
>           4  Thescelosaurus
>           5  Agilisaurus
>            6A  Heterodontosaurus
>             B  Chaoyangsaurus
>             Ca  Homalocephale
>              b  Pachycephalosaurus
>              D  Psittacosaurus
>               E  Protoceratops
>                Fa  Triceratops
>                 b  Pachyrhinosaurus
>             7  Hypsilophodon
>              8  Tenontosaurus
>               9  Gasparinisaura
>                10  Dryosaurus
>                 11  Camptosaurus
>                  12  Iguanodon
>                   13  Probactrosaurus 
>                    14  Ouranosaurus {{Hadrosauridae}}
>                     15a  Lambeosaurus
>                       b  Hadrosaurus

  If this list gets too long, please note that there is a lot of
internal variation that cannot be bundled up into a set of a
few, neat little taxa. I've also dropped everything down to the
best, diagnostic taxa as utility for distribution. And I've
indented the lines.

Jaime A. Headden

  Where the Wind Comes Sweeping Down the Pampas!!!!

Do You Yahoo!?
Get personalized email addresses from Yahoo! Mail - only $35 
a year!  http://personal.mail.yahoo.com/