Re: First International Phylogenetic Nomenclature Meeting

[David Marjanovic <david.marjanovic@gmx.at>]

----- Original Message -----
From: "Mickey Mortimer" <Mickey_Mortimer111@msn.com>
To: <dinosaur@usc.edu>
Sent: Tuesday, June 15, 2004 11:49 PM
Subject: First International Phylogenetic Nomenclature Meeting

> 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).

That name _really_ cries for an apomorphy-based definition. The apomorphy is
very unambiguous (unlike "powered flight" or "feathers"), and fossils around
the base of Diapsida often include skulls, so I don't see a serious problem
here.

> Rhynchocephalia Guenther 1867 = Apomorphy (1st lepidosaur with Sphenodon
> punctatus' premaxillary chisels).

Probably similarly unambiguous. I just hope we can use *Sphenodontida* or
suchlike for the stem. :-)

> Crurotarsi Sereno and Arcucci 1990 = Apomorphy (1st archosaur with Caiman
> crocodilus' fully rotary, hemicylindrical, fibulocalcaneal crurotarsal
articulation).

Should better retain its original stem-based definition. Ah, this will be
replaced with *Pancrocodylia*...

> 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?

Recommendation 11A Example 1 (http://www.ohiou.edu/phylocode/art11.html,
scroll down far down) agrees with you -- the example being *Dinosauria*.

> Reptilia Laurentus 1768 = Crown (Chelonia mydas + Sphenodon punctatus +
> Draco volans + Caiman crocodilus + Vultur gryphus).

People will consider it proven that phylogenetic nomenclature is crazy.
        Laurentius, BTW.

> Sauria MacCartney 1802 = Crown (Sphenodon punctatus +
> Draco volans + Caiman crocodilus + Vultur gryphus).

Why *Draco*?
I've never seen Sauria being used precladistically in anywhere near this
sense. It's always used as a synonym of the rarer name Lacertilia -- the
paraphyletic lizards without snakes and sometimes amphisbaenians.

> The good ol' node-stem triplet of Sauria, Lepidosauromorpha and
> Archosauromorpha is destroyed by Gauthier et al. as well.

Isn't all that old... Why not *Neodiapsida* instead of *Sauria*? Usually
names starting with Neo- describe much smaller clades than the corresponding
prefix-less names; the current *Neodiapsida* includes almost all diapsids.
I'd like a solution similar to *Sauropoda* -- *Eusauropoda* -- 
*Neosauropoda*, *Theropoda* -- "Eutheropoda" -- *Neotheropoda* and *Aves* -- 
*Euornithes* -- *Neornithes*.

> Archosauromorpha von Huene 1946 = Node (Protorosaurus speneri +
> Rhynchosaurus articeps + Caiman crocodilus).

This is really weird. Why not keeping it stem-based?

> 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?

Perhaps just to be really certain, so that the BANDits can't complain?

> Luckily, Reisz has better definitions for some of the above clades-
> Reptilia: Clade (Testudo hermani, Crocodylus niloticus, Sphenodon
punctatus,
> Iguana iguana)

First, *T. hermanni*. Second, I don't like this either; see my abstract.

> Diapsida: Clade (Petrolacosaurus kansensis, Iguana iguana, not Captorhinus
> aguti, Procolophon trigoniceps, Paleothyris acadiana)

Currently a heterodefinitional synonym of the apomorphy-based one. Could
stay so.

> As does Sereno (gasp!)-
> Archosauria: Crown Clade (Crocodylus niloticus and Passer domesticus)

Fine, fine. But using a nonavian dinosaur would have been even better (Rec.
11A).

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

=8-)

> 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,
> Othnielia rex, Zephyrosaurus schaffi, Yandusaurus hongheensis)
> Hadrosauriformes: Clade (Iguanodon bernissartensis and Parasaurolophus
> walkeri)
> Hadrosauroidea: Clade (Parasaurolophus walkeri not Iguanodon
> bernissartensis)

Awww!

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

*S. armatus* is the type. *S. stenops* is better known... or at least much
more famous. Has more beautiful plates.

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

Weird. Really.

> 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)

I agree. But only one of these two definitions can survive!

> 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!

Oh, they aren't even the problem. If he's right, then *Pterosauria* _does
not exist_. Why? Because *Pterosauromorpha* is defined as a part of
*Archosauria* -- and at least *Longisquama* is most likely not an archosaur.

The problems with foggy apomorphies is recognized, though. Recommendations
9E and 9F (at the bottom of http://www.ohiou.edu/phylocode/art9.html) are
meant to deal with this problem. Let's hope they will be followed.

> 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.

Hm.

> 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_ Av[i]filopluma),
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

I hope Recommendations 9E and 9F will be followed at length. Otherwise the
name is going to be forgotten.