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The iguanodont paper
Working on the iguanodont paper further exposed problems with the current
system of cladistic taxonomy that I also discussed in Dinosaurs of the Air.
Currently a large group of ornithopods is easily named by a single word as
hadrosaurs. This is an accident in that the group was taxonomically lucky
enough to
have gone extinct before they left descendents. Had they done so then they
would
not be known under the cladistic system as hadrosaurs. Instead they would be
known as say, nongeekosaur hadrosaurs -- i.e. at least two words would be
needed to label the duckbilled dinosaurs.
Iguanodonts lasted at least as long as hadrosaurs, probably inhabited more
continents, and as the CR paper helps show with the increase in genera, were at
least as anatomically diverse. Yet there currently is no name that
incorporates all the dominant large, spike thumbed, styracostenan ornithopods.
To be blunt, this arrangement is bizarre to the point of being wacky. What
other classification system labels things as much but what they are not as by
what they are? Imagine someone saying "look son, aren't the fluffy
noncumulonimbus cumulus clouds pretty?" Or "children, as your text book says,
elephants are
nonbat mammals." The system is not just technically awkward. It is a
significant PR problem, in that it is a classic case of excessive techno jargon
that
confuses the public, large sections of which are already skeptical of
paleontological science -- it further detaches the scientists from the public.
Nonhadrosaur iguanodontoids is even harder for folks to grasp than is
iguanodontids.
Iguanodontids could be defined as iguanodontoids excluding hadrosaurids. No
muss, no fuss. Thecodonts could be archosauromorphs excluding dinosauromorphs
and pterosauromorphs (and perhaps crocodylomorphs, although it could be argued
that they are the last surviving thecodonts).
The revival of a name that conveniently labels the basal archosaurs is not
going to adversely impact the bird origins controversy. For one thing, the
anti-dinosaur people are detached from reality anyway so they are going to do
what
they do no matter what is done with the taxonomic system. Also, basal
archosaurs are also defined by the exclusion of dinosaurs and pterosaurs, so
there is
no practical difference except that the current system is linquistically more
awkward.
Not that I am holding my breath expecting anything to happen on this. Might
require many years before people realize a need for change.
I am collaborating with others to continue to work on Brit iguanodonts. In
particular am looking forward to describing and naming the mystery specimen
with
the long jaw and super massive arm figured by Richard (bug eye) Owen that is
so forgotten that its exact stratigraphic level is not currently known (other
than below the high tide level at a location on the coast). I stumbled upon
this while checking out the correct spelling of âI.â hoggii in the original
publication. "I." dawsoni and "I. " fittoni also need dealing with. It is
important that from now on iguanodont specimens be assigned to a specific genus
or
species only if it can be solidly justified, No more tossing European
Barremian-Aptian specimens into either robust I. bernissartensis or gracile
"I."
atherfieldensis, or anything outside Europe into Iguanodon unless it can be
shown to
be the same basic beast as the specialized Bernissart robust genus.
GSPaul
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