Message 2004-06-0029: First International Phylogenetic Nomenclature Meeting [amniote vertebrate clades]

Wed, 16 Jun 2004 07:03:57 -0700 (PDT)

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Date: Wed, 16 Jun 2004 07:03:57 -0700 (PDT)
From: "T. Michael Keesey" <>
To: Mailing List - PhyloCode <>
Subject: First International Phylogenetic Nomenclature Meeting [amniote vertebrate clades]

--- "Jaime A. Headden" <> wrote:
>   I should hope that Crurotarsi is not replaced by "Pancrocodylia," if the
> latter is ever named. The latter is misused and ugly, and Crurotarsi names
> a different kind of clade.

They are not equivalent. _Crurotarsi_ was originally named as a node-based
clade within _Pseudosuchia_ (the panstem), IIRC.

(Incidentally, "Pancrocodylia" makes a far better name for the panstem than
_Pseudosuchia_, FWIW.)
> << Archosauromorpha von Huene 1946 = Node (Protorosaurus speneri +
> Rhynchosaurus articeps + Caiman crocodilus).>>
>   I wonder if we should be using *Archosaurus rossicus*? I know the name
> was coined post-Archosauria. Gauthier/deQuieroz/etal., guys should note
> the recommendation that the specifier for a clade, if named AFTER a taxon,
> should include that taxon.

I'm not sure what you're trying to say here, but, since _Archosaurus_ was named
after _Archosauria_, _Archosauria_ is not required to have it as an internal
specifier. See Rule 11.8 -- it only applies when the clade is named *after* the

> *Rhynchosaurus* should not be used, rather
> *Sphenodon,* since Rhynchocephalia was named to include IT, and it is not
> eponymous to *Rhynchosaurus.* That name should be used as the first
> internal anchor to Rhynchosauria, though, a subclade of Rhynchocephalia.

Rhynchosaurs are not rhynchocephalians. _Rhynchocephalia_ is in non-squamatan
_Lepidosauria_, while _Rhynchosauria_ is in non-archosaurian _Archosauromorpha_
(or "Panarchosauria"). Using _Sphenodon_ as an internal specifier for
_Archosauria_ would make it a hetereodefinitional synonym of _Sauria_, which
follows nobody's prior usage.

(Incidentally, I believe the original usage of Archosauria included some
synapsids, so it would be useless to try and go back to the original sense. It
would be equivalent to _Amniota_.)

> <<Neornithes finally gets an official definition, from Sereno- Neornithes:
> Crown Clade (Passer domesticus not Crocodylus niloticus)>>
>   Wow. The fossil lineage of neornitheans.... Aves should be used for the
> crown, and Neornithes the internal node for Palaeognathae + Neognathae (AS
> USED). Good lord. People want *Archaeopteryx* as a member of Aves too bad.

This would make _Neornithes_ a synonym of _Aves_. (Not that this would
necessarily be a bad thing.)
Mickey Mortimer wrote:
> <<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)>>

Yes, these directly violate Rule 11.8, which states, "[W]hen a clade name is
converted from a preexisting genus name or is a new or converted name derived
from the stem of a genus name, the definition of the clade name must use the
type species of that genus name at the time of establishment as an internal
specifier." It will be interesting to see whether the paper addresses this
issue, and comes out against the rule. IMHO, it is a good rule, and would
prevent, for example, Sereno's definition of _Ceratosauria_ (anchored on
_Coelophysis_), which probably does not include _Ceratosaurus_.

=====> T. Michael Keesey <>
=====> The Dinosauricon <>
=====> Instant Messenger <Ric Blayze>

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