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RE: [dinosaur] Tyrannosaurs and Deinodons (was re New Konzhukovia species (temnospondyl) from Permian of South America + Early Triassic polar coprolites + more papers




 
> Date: Thu, 14 Apr 2016 10:25:25 +1000
> From: tijawi@gmail.com
> To: dinosaur-l@usc.edu
> Subject: Re: [dinosaur] Tyrannosaurs and Deinodons (was re New Konzhukovia species (temnospondyl) from Permian of South America + Early Triassic polar coprolites + more papers
>
> Anthony <keenir@hotmail.com> wrote:
>
> > Then what's the problem? the -oidea and such would be a legacy of its past,
> > and would be less noteworthy than that we English-speakers say we wear shoes
> > and not shoen (its the same thing - just in two early modern dialects)
>
> I thought the problem was clear - it was spelled out in Matt's post.
> The ICZN and phylogenetic nomenclature (PN) have different rules
> regarding how to treat certain taxa (coordinated family-level taxa -
> such as families and superfamilies).
>
> In the eyes of the ICZN, the -oidea of Tyrannosauroidea designates it
> as a 'superfamily'. As such, it is linked to Tyrannosauridae, which
> the ICZN regards as a 'family'. Both Tyranosauridae and
> Tyrannosauroidea therefore fall under the jurisdiction of the ICZN,
> and must conform to rules regarding priority. A strict application of
> ICZN rules would say that Tyrannosauridae should be replaced by
> Deinodontidae - because both _Tyrannosaurus_ and _Deinodon_ belong in
> the same family, and Deinodontidae was named first. As an extension
> of this, Deinodontoidea would replace Tyrannosauroidea, under ICZN
> rules. I think this approach is a bad idea.
 
Were Deinodontidae and Deinodontoidea actually created, or is their existence assumed based on backforming from _Deinodon_ & the higher clades which were named for _Tyrannosaurus_?
(I've seen backforming in linguistics, but not in nomenclature)
 
> Under PN, on the other hand, Tyranosauridae and Tyrannosauroidea are
> defined as clades. Being a 'family' and 'superfamily' makes no
> difference at all - they are treated the same as any other clade.
> Deinodontidae and Deinodontoidea are not defined as clades, so they
> have no standing under PN. They do not exist. This is fine by me.
 
So, because Cope and Marsh forgot to define Deinodon's clades, we can't use it?  :)
 
Why not define it as "Tyrannosaur(__) + {insert name here}" ?
 
for example, if the Tyrannosaurids are defined by, among other things, having two-fingered hands, let Deinodontidae/oidea be the Tyrannosaurids+the three-fingered species that gave rise to them.  (or was a sister species to the mother of the Tyrannosaurids)
 
 
> > if Coeluroidea gets defined next week or next year, it has priority over the
> > older definition of Tyrannosauridea? even if that's true (and not an
> > understandable misinterpretation or misreading), wouldn't that only matter
> > if Coeluroidea is given the exact same definition of Tyrannosauridea?
>
> It doesn't matter to ICZN. According to ICZN, a family (or
> superfamily) doesn't need a definition in order to be valid.
>
> This is how ICZN rules regarding families (-idae) and superfamilies
> (-oidea) complicate things in PN. PN says a clade needs a definition
> in order to be valid.
 
So...to make sure I'm understanding this...under PN, it doesn't matter if _Ceratops_ is a valid genus -- it can be used as a higher clade name anyway?
 
>  The ICZN only looks at which family was *named*
> first. It doesn't care about phylogenetic definitions.
 
So, the ICZN assumes that, if something has a name, there's no need to worry about finding a place for it - it  already has one?
 
That does sound handy.
 
> (In its defense, the ICZN Code was crafted in the epoch of Linnaean
> ranks, long before PN came on to the scene. But now it's time to move
> on, and abandon the ICZN's role in the naming of families etc. The
> ICZN can stick to genera and species.)
 
But why stop at that half-measure?  Why not give the boot to the ICZN genera and species (and subspecies and superspecies and subgenera and other things I've heard of over the years) ?   What makes genus and species  worth saving, when nothing else is?