Re: Iguanodontidae

["Tim Williams" <twilliams_alpha@hotmail.com>]

Jaime Headden wrote:

> Recently this thread has taken a satisfying turn: discussing the species
> complex for *Iguanodon.*


You betcha.  I have only a few things to add.

(1) The discovery of a new North American iguanodontian from the Garden of
the Gods site, mentioned (and very briefly described) by Bakker (1998) may
help elucidate the phylogeny of _Iguandon_ and _Camptosaurus_.  Or it may
complicate it even further.  Time will tell.  The skull doesn't appear to be
true _Iguanodon_ though, based on Bakker's illustration.

(2) Norman (1998 - the _Altirhinus_ paper) revived the genus _Cumnoria_ for
the British iguanodontian species _Camptosaurus prestwichii_, but he did not
say why he was removing it from the genus _Camptosaurus_.  I think this is
interesting given Jaime's doubts regarding _C. prestwichii_'s referral to
_Camptosaurus_.

(3) The large Australian ornithopod _Muttaburrasaurus_ Bartholomai and
Molnar 1981 seems to be increasingly secure *outside* of the Iguanodontia;
_Muttaburrasaurus_ was once regarded as a camptosaurid, or at least close to
the "thumb-spiked" iguanodontians.  The alleged thumb-spike is apparently an
indeterminate bone fragment, and _Muttaburrasaurus_ appears to be more
closely related to certain Aussie hypsilophodontids.

(4) The poorly known east European ornithopod _Bihariosaurus_ Marinescu,
1989 probably has nothing useful to add to iguanodontian phylogeny.  The
"diagnostic" features of this ?camptosaurid look suspiciously like juvenile
traits.  If anyone can point me to a single unique character in this
specimen, please let me know.



Tim

------------------------------------------------------------

Timothy J. Williams

USDA/ARS Researcher
Agronomy Hall
Iowa State University
Ames IA 50014

Phone: 515 294 9233
Fax:   515 294 3163

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