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Greg Paul's new (or newly named) iguanodonts



A paper I've been waiting for since SVP 2006 is finally in the "Forthcoming
Articles" list on Cretaceous Research. Someone has also made the preprint
available at:
http://www.4shared.com/file/31263941/b585bb7a/Iguanodont_diversity.html

Paul, G.S. A revised taxonomy of the iguanodont dinosaur genera and species,
Cretaceous Research 
(2007), doi: 10.1016/j.cretres.2007.04.009

Note that this preprint states: "This is a PDF file of an unedited
manuscript that has been accepted for publication. As a service to our
customers we are providing this early version of the manuscript. The
manuscript wil undergo copyediting, typesetting, and review of the resulting
proof before it is published in its final form. Please note that during the
production process errors may be discovered which could 
affect the content, and al legal disclaimers that apply to the journal
pertain."

So in principle even the names could change before final publication.

Here are Greg Paul's new formerly-Iguanodon taxa:

Dakotadon lakotaensis n. gen
Dollodon bampingi n. gen. et sp.

Abstract
Criteria for designating dinosaur genera are inconsistent; some very similar
species are highly split at the generic level, other anatomically disparate
species are
united at the same rank. Since the mid-1800s the classic genus Iguanodon has
become a
taxonomic grab-bag containing species spanning most of the Early Cretaceous
of the
northern hemisphere. Recently the genus was radically redesignated when the
type was
shifted from nondiagnostic English Valanginian teeth to a complete skull and
skeleton of
the heavily built, semi-quadrupedal I. bernissartensis from much younger
Belgian
sediments, even though the latter is very different in form from the gracile
skeletal
remains described by Mantell. Currently, iguanodont remains from Europe are
usually
assigned to either robust I. bernissartensis or gracile I. atherfieldensis,
regardless of
location or stage. A stratigraphic analysis is combined with a character
census that shows
the European iguanodonts are markedly more morphologically divergent than
other
dinosaur genera, and some appear phylogenetically more derived than others.
Two new
genera and a new species have been or are named for the gracile iguanodonts
of the
Wealden Supergroup; strongly bipedal Mantellisaurus atherfieldensis Paul,
2006
(holotype BMNH R5764) which possesses a camptosaur-like ilial shape, and the
long
snouted, long bodied, small hipped, semi-bipedal Dollodon bampingi gen. nov.
sp. nov.
(holotype IRSNB 1551) which has a shallow ilium. Insufficiently diagnostic
I. hoggii is
removed from the earlier Camptosaurus. Poorly described I. dawsoni, I.
fittoni and I.
hollingtoniensis are removed from the much later and more derived Iguanodon
and
considered Ornithopoda incertae sedis pending redescription. The synonymy of
I. fittoni
and I. hollingtoniensis has not been confirmed. A set of remains of similar
age to I. fittoni
and I. hollingtoniensis appear to combine a specialized, elongate dentary
with massive
arms: it either belongs to one of the contemporary taxa, or is a new,
unnamed taxon.
There has recently been a tendency to consider iguanodonts spatially remote
from I.
bernissartensis to be members of or very similar to the type species, but
reanalysis finds
that I. orientalis is not a junior synonym of I. bernissartensis and is a
nomen dubium, and
that basal I. lakotaensis is not a member of Iguanodon and accordingly is
assigned the
new genus Dakotadon gen. nov. (holotype SDSM 8656). Dakotadon is probably
basal to
Iguanodon and not an iguanodontoid. The higher taxonomy of iguanodontoids is
confused due to phylogenetic problems, and inconsistent definitions of the
Iguanodontidae (which as currently defined appears to be limited to
Iguanodon) and
Hadrosauroidea. Mantellisaurus and especially Dollodon, for instance, are
probably more
derived than Iguanodon: they may be hadrosauroids depending on which
phylogenetic
definition of the term is preferred.

Thomas R. Holtz, Jr.
Email: tholtz@umd.edu   Phone: 301-405-4084
Office: Centreville 1216                        
Senior Lecturer, Vertebrate Paleontology
Dept. of Geology, University of Maryland
http://www.geol.umd.edu/~tholtz/
Fax: 301-314-9661               

Faculty Director, Earth, Life & Time Program, College Park Scholars
http://www.geol.umd.edu/~jmerck/eltsite/
Fax: 301-405-0796

Mailing Address:        Thomas R. Holtz, Jr.
                        Department of Geology
                        Building 237, Room 1117
                        University of Maryland
                        College Park, MD 20742 USA