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

> Date: Tue, 12 Apr 2016 16:27:33 +1000
> From: tijawi@gmail.com
> To: dinosaur-l@usc.edu
> Subject: Re: [dinosaur] New Konzhukovia species (temnospondyl) from Permian 
> of South America + Early Triassic polar coprolites + more papers
> Mickey Mortimer <mickey_mortimer111@msn.com> wrote:
>> Apparently the misunderstanding where authors think family-level groups 
>> can't be based on nomina dubia extends to non-dinosaurian taxa as well.
> Yes, family-level groups *can* be based on nomina dubia - this is
> allowed by the ICZN. But the question is: *should* family-level
> groups be based on nomina dubia? I don't think they should be. Do we
> have to replace Tyrannosauridae with Deinodontidae, simply because
> Deinodontidae was named first? This seems like the nomenclatural
> equivalent of political correctness gone mad.

There should be a petition to the ICZN in that case, and also a detailed 
redescription of Deinodon's syntypes that compared them in depth to other 
taxa.  Currently, everyone's operating under the untested assumption that 
Russell's 46 year old statement they can't be distinguished from 
albertosaurines or Daspletosaurus is true.  If the new study found they 
couldn't be distinguished from e.g. Bistahieversor or Appalachiosaurus, which 
are outside Tyrannosauridae, then that would be a great case for suppressing 

> A family-level group is a clade, and the clade needs to be defined
> using the nominal taxon. So if we use the family Deinodontidae in
> preference to Tyrannosauridae, then we have to use _Deinodon_ as a
> specifier. That means we have to include _Deinodon_ in a phylogenetic
> analysis. But if _Deinodon_ is crap, then there's no point including
> it in a phylogenetic analysis. It would be done simply for
> bookkeeping reasons - there is no valid scientific reason.

It doesn't mean we have to include Deinodon in an analysis, only that we have 
to use evidence to place it somewhere in a phylogeny.  Maybe that would be 
morphometric evidence, as that's commonly used based on expansions of Smith's 
tooth measurement sample.  Of course adding Deinodon to a phylogenetic analysis 
is itself scientifically interesting- to tell us something quantitative about 
where it belongs in the tree of life.

> This issue of priority may come up again, from another direction.
> Some phylogenetic analyses find _Coelurus_ to belong to the
> Tyrannosauroidea. In this case, ICZN 'rules' would require that the
> Tyrannosauroidea be renamed Coeluroidea (because Coeluridae was named
> before Tyrannosauridae). This is silly.

Here's the thing (and we've probably been over this before, but I forget your 
answer...)- Yeah, renaming Tyrannosauroidea Coeluroidea is silly.  But why are 
you against petitioning the ICZN to prevent this, instead of just ignoring the 
rules whenever you think they don't function well?  That is the reason 
petitioning exists, after all.  

> I know this is a well-worn argument; but once family-level taxa were
> converted into clades, I see no reason why ICZN 'rules' are necessary
> when it comes to priority.

I don't think phylogenetic nomenclature has anything to do with this.  If we 
didn't have a phylogenetic definition for Tyrannosauroidea or Tyrannosauridae, 
you'd no doubt still think using Deinodontidae and Coeluroidea is silly.  Right?

Mickey Mortimer
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