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Date: Mon, 10 Oct 2005 20:35:37 +0200 (MEST)
From: [unknown]
To: dinosaur@usc.edu, phylocode@ouvaxa.cats.ohiou.edu
Subject: =3D?ISO-8859-1?Q?Re:_Stormbergia_dangershoeki,_new_Early_Jurassic_or=
> --- Urspr=FCngliche Nachricht ---
> Von: "T. Michael Keesey" <keesey@gmail.com>
> Datum: Mon, 10 Oct 2005 10:03:52 -0700
>
> (apologies for cross-posting)
I add apologies for the length!
> [...] I think there is also some kind of
> responsibility with converted names to accord with historical usage=
.
> For example, _Maniraptora_ was initially defined as a stem-based cl=
ade
> specified internally by _Aves_ (sensu stricto) and externally by
> _Ornithomimus_, and that's all it has ever meant. Nobody wants to
> change the definition if certain taxa, like _Tyrannosauroidea_ or
> _Therizinosauria_, fall inside or out under various topologies,
> because it's intrinsically understood as a stem-based clade.
Good point.
> [...] Then there are taxa like _Euornithopoda_, not converted from
> traditional taxa, but named after them--a blurry area in between.
Proposal:
--------------------------------
Recommendation, maybe even Rule:
Clade names created by adding a prefix to another clade name should/m=
ust be=20
defined in a manner consistent with the meaning of the prefix.
Example 1: *Euornithopoda* (author, year) should/must be defined in s=
uch a=20
way that it can maximally be a junior heterodefinitional synonym of=
=20
*Ornithopoda* (author, year), assuming that both names are to be defi=
ned.=20
The reason is that eu- means "good, true" in Classical Greek and has=
=20
historically been used to designate taxa within those described by th=
e=20
corresponding prefixless names.
Example 2: *Panarthropoda* (author, year) should/must be defined in s=
uch a=20
way that it can minimally be a junior heterodefinitional synonym of=
=20
*Arthropoda* (author, year), assuming that both names are to be defin=
ed.=20
The reason is that pan(to)- means "all" in Classical Greek [someone w=
ho=20
actually knows Classical Greek should correct this if necessary!] and=
has=20
historically been used to designate taxa that include those described=
by=20
the corresponding prefixless names.
-----------------------------------
As you can see, I can't find a good wording for this...
"Maximally" and "minimally" are supposed to mean "if it is as=
=20
inclusive/exclusive as possible".
At least some of the prefixes in question have also been used fo=
r=20
other purposes, for example the genus *Euparkeria* was named because =
a=20
totally different genus *Parkeria* already existed; their contents ar=
e not=20
going to overlap. Probably we should explicitely exclude these cases =
=66rom=20
the above proposal.
(About the examples: Currently Euornithopoda is used for what=
=20
botanists would probably call the "core ornithopods", and Panarthropo=
da=20
includes everything that was ever referred to Arthropoda, which in cu=
rrent=20
usage means Onychophora + Tardigrada + Arthropoda + a load of Cambria=
n=20
fossils.)
We might (!) maybe (!) want to extend this to the suffixes prescribed=
by=20
the existing Codes for certain ranks, and/or to some suffixes that ha=
ve=20
become fashionable for other purposes, like -iformes and -omorpha.
(This, too, would require an exception for some genus names --=
=20
zoological superfamilies must end in -oidea, but *Emydoidea* is a val=
id=20
genus name that designates the sister-group of *Emys* after which it =
is=20
named. Or, again, we might want to outlaw this to eliminate potential=
=20
confusion -- at the risk of losing some quite popular names.)
> Then again, some taxa, like _Dinosauria_ and _Archosauria_, have be=
en
> embraced as defined clades, so maybe it's just a matter of overturn=
ing
> everybody's preconceptions, one taxon at a time.
>
> Good luck...
The Companion Volume will be everything but "one taxon at a time" (an=
d for=20
different reasons that's a good thing). It will have no such luck at =
all.
BTW, these are actually special cases. Dinosauria is almost a new tax=
on=20
like Maniraptora because its monophyly was only re-recognized shortly=
=20
before its first phylogenetic definition was coined. Before that it h=
ad=20
been considered polyphyletic for decades, and had therefore hardly be=
en=20
used in the primary literature. Archosauria was phylogenetic grass be=
fore=20
its first phylogenetic definition was coined, and the paper that did =
that=20
(and also included the first cladistic analysis of the group) also su=
pplied=20
a name for the clade that includes all traditional archosaurs, namely=
=20
Archosauriformes. The dissenters (who still exist, but in reduced num=
bers)=20
have no name for the clade called Archosauria by the majority; this=
=20
disadvantage seems to outweigh the advantage of keeping the tradition=
al=20
contents of Archosauria.
--=20
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DSL-Flatrate f=FCr nur 4,99 Euro/Monat* http://www.gmx.net/de/go/dsl