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Re: another diatribe



In a message dated 96-04-19 14:19:49 EDT, nking.ucs@smtp.usi.edu
(King, Norm) writes:

>As an addendum to my earlier rambling diatribe, I point out that
>renaming _Lagosuchus_ has led to considerable nomenclatorial
>instability, none of which was necessary.  ICZN rules are partially
>_intended_ to promote just the opposite--stability.  Will we also
>end up with a family Rioarribasauridae?

Not a bad idea, considering the nice series of _Rioarribasaurus_
remains we have from Ghost Ranch; but other family names have priority
and cannot yet be discarded as doubtful.

_Lagosuchus_ hasn't been renamed. But we now know the name refers to
(apparently) non-diagnostic lagosuchian material, and that what we
have all been (incorrectly) citing as _Lagosuchus_ should now be
called _Marasuchus_.  Likewise, _Coelophysis_ has not been renamed,
but the best-known material (from Ghost Ranch) has been placed in the
genus _Rioarribasaurus_, because the _Coelophysis_ material is
(apparently) doubtful.

All those "apparently" comments are inserted because the final
consensus is not yet in, of course. The _Coelophysis_ material may
turn out to be diagnostic and different from the Ghost Ranch theropod
material (see my article, "Little Dinosaur, Big Controversy" on the
Skullduggery home page), and the _Lagosuchus_ material may also turn
out to be diagnostic and different from _Marasuchus_ material.

>I reiterate something from an even earlier diatribe that dealt with
>what seems like nomenclatorial chaos.  It's not much of a problem
>when I tell people that we don't use the name _Trachodon_ any more,
>but we think that much of what was called _Trachodon_ at one time
>has been referred to as _Anatosaurus_.  In fact, I tell people that
>one way they can judge whether a "coffee table" book or kid's book
>on dinosaurs was written by someone who knows what he/she is talking
>about is to check to see if _Trachodon_ is used for duckbills, and
>don't buy the book if it is!  When I say that apparently
>_Anatosaurus_ should now be called _Anatotitan_, people's eyes start
>to glass over.  They want to know what it's going to be called next,
>and why they should bother learning _Anatotitan_.

The _Anatotitan_ business differs from the _Lagosuchus_ and
_Coelophysis_ business in that _Anatosaurus_ (the genus into which the
present type species of _Anatotitan_ was originally placed) is not a
doubtful name but has turned out to be a junior synonym of the equally
well established name _Edmontosaurus_: _except for_ the species
_Anatosaurus copei_, which really does belong in a different genus
(according to the way hadrosaurids are presently classified). It
should have been placed in a different genus way back in 1942, when
Lull & Wright created _Anatosaurus_. So _Anatosaurus_ has not been
renamed _Anatotitan_; if anything, it has been renamed
_Edmontosaurus_. Times change.

_Trachodon_ was established by Leidy in 1856 for a single Judith River
tooth that C. M. Sternberg and Lull & Wright long ago agreed probably
belonged to a lambeosaurid (based on the angle of the enameled surface
to the root). It's usage for a hadrosaurid likely stems from Osborn
and Lambe's work around the turn of the century, when they referred
all kinds of hadrosaurid remains (that included teeth) to that
genus. Since Osborn had the powerful publicity machinery of the
American Museum of Natural History at his beck and call, he was able
to pound _Trachodon_ into the minds of early 20th-century dinosaur
aficionados, particularly after mounting the two _Anatotitan_
skeletons side by side at the AMNH and labeling them "trachodont"
dinosaurs (confusing the genus with the family
Trachodontidae). Needless to say, the genus _Trachodon_ is toast. Not
even Jack Horner can match the type tooth unambiguously to any one
duckbill genus.