First International Phylogenetic Nomenclature Meeting

[Mickey Mortimer <Mickey_Mortimer111@msn.com>]

As David pointed out, the abstracts for this are online-
http://www.ohiou.edu/phylocode/IPNM.pdf .  Congratulations to him for
authoring an abstract himself.  I've not read the whole thing yet, but the
number of definitions I find problematic amazes me.

First, we have Gauthier's continuing insistance on apomorphy-based clades,
which will only lead to uncertain placement on the cladogram and uncertain
application to intermediate states.
Diapsida Osborn 1903 = Apomorphy (1st reptile with Caiman crocodilus' two
temporal arches/fenestra).
Rhynchocephalia Guenther 1867 = Apomorphy (1st lepidosaur with Sphenodon
punctatus' premaxillary
chisels).
Crurotarsi Sereno and Arcucci 1990 = Apomorphy (1st archosaur with Caiman
crocodilus' fully rotary,
hemicylindrical, fibulocalcaneal crurotarsal articulation).

Gauthier et al. also define Reptilia and Sauria to include Aves!  I mean,
sure birds are near certainly reptiles, but why should we force it?
Reptilia Laurentus 1768 = Crown (Chelonia mydas + Sphenodon punctatus +
Draco volans + Caiman
crocodilus + Vultur gryphus).
Sauria MacCartney 1802 = Crown (Sphenodon punctatus + Draco volans + Caiman
crocodilus + Vultur
gryphus).

The good ol' node-stem triplet of Sauria, Lepidosauromorpha and
Archosauromorpha is destroyed by Gauthier et al. as well.
Sauria MacCartney 1802 = Crown (Sphenodon punctatus + Draco volans + Caiman
crocodilus + Vultur
gryphus).
Archosauromorpha von Huene 1946 = Node (Protorosaurus speneri +
Rhynchosaurus articeps + Caiman
crocodilus).

Finally, Gauthier et al. add Compsognathus to the definition of Archosauria-
Archosauria Cope 1869 = Crown (Caiman crocodilus + Compsognathus longipes +
Vultur gryphus).
Just why are dinosaurs constrained as archosaurs?  And why not use
Megalosaurus bucklandii instead?

Luckily, Reisz has better definitions for some of the above clades-
Reptilia: Clade (Testudo hermani, Crocodylus niloticus, Sphenodon punctatus,
Iguana iguana)
Diapsida: Clade (Petrolacosaurus kansensis, Iguana iguana, not Captorhinus
aguti, Procolophon
trigoniceps, Paleothyris acadiana)
As does Sereno (gasp!)-
Archosauria: Crown Clade (Crocodylus niloticus and Passer domesticus)

Neornithes finally gets an official definition, from Sereno-
Neornithes: Crown Clade (Passer domesticus not Crocodylus niloticus)

But he still can't get the hang of defining clades based on eponymous taxa-
Nodosauridae: Clade (Panoplosaurus mirus not Ankylosaurus magniventris)
Nodosaurinae: Clade (Panoplosaurus mirus not Sarcolestes leedsi,
Hylaeosaurus armatus, Polacanthus foxii)
Iguanodontia: Clade (Parasaurolophus walkeri not Hypsilophodon foxii,
Thescelosaurus neglectus, Parksosaurus warreni, Orodromeus makelai,
Othniellia rex, Zephyrosaurus schaffi, Yandusaurus hongheensis)
Hadrosauriformes: Clade (Iguanodon bernissartensis and Parasaurolophus
walkeri)
Hadrosauroidea: Clade (Parasaurolophus walkeri not Iguanodon
bernissartensis)

And isn't the type species of Stegosaurus S. armatus?  Why does he use S.
stenops?  Wagner knows to use S. armatus.

Interestingly, Neornithischia seems to be the marginocephalian stem-
Neornithischia: Clade (Triceratops horridus not Ankylosaurus magniventris,
Stegosaurus stenops and Parasaurolophus walkeri)

And Sereno's always right, of course, so let's define Heterodontosaurus to
be an ornithopod! ;-)
Ornithopoda: Clade (Heterodontosaurus tucki and Parasaurolophus walkeri)
I'll be using Wagner's definition-
Ornithopoda: Clade (I. bernissartensis not A. magniventris, S. armatus, or
C. montanus)

More apomorphy-based definitions, this time from Padian-
Pterosauria (Pterosauromorpha with fourth metacarpal and digit hypertrophied
to support wing membrane
synapomorphic with Pterodactylus antiquus)
Pterodactyloidea (Pterosauria with metacarpus at least 80% as long as
humerus synapomorphic with
Pterodactylus antiquus)
So imagine Peters is right, and Longisquama and Sharovipteryx are the
closest relatives of pterosaurs AND have elongated fourth manual digits that
support membranes.  They'd be pterosaurs.  Or are they not _wing_ membranes
because they weren't used for flight?  But if Sharovipteryx glided using its
leg-wings, do its tiny arm wings count because they assist flight?  Ugh.
Apomorphy-based definitions MUST STOP!

Clarke et al. define some names-
Theropoda Marsh 1881 = Branch (Allosaurus fragilis, not Plateosaurus
engelhardti).
Why not Megalosaurus bucklandii?!  They use Megalosaurus for Dinosauria and
Saurischia.

Finally, they give us a new, difficult to apply name-
Avipluma New = Apomorphy (1st theropod with Vultur gryphus' hollow-based,
branched, filamentous
epidermal appendages [= feathers]).
Yeah... so that's probably less inclusive than Avetheropoda, perhaps as
inclusive as the Sinosauropteryx+Vultur node (_currently_ Avefilopluma), and
definitely as inclusive as Maniraptora.  Wow, the utility is astounding :-|

Mickey Mortimer
Undergraduate, Earth and Space Sciences
University of Washington
The Theropod Database - http://students.washington.edu/eoraptor/Home.html