[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

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



The confusion here comes from mixing two totally distinct nomenclatural systems (ICZN and phylogenetic pre-PhyloCode nomenclature). As far as the ICZN is concerned, neither Coeluroidea nor Tyrannosauroidea nor Deinodontoidea need phylogenetic definitions, let alone monophyletic ones. Even if Coelurus is closer to Tyrannosaurus than to Aves, Coeluroidea could be treated, under the ICZN, as a basal grade from which Tyrannosauroids evolved, or as monotypic including only Coelurus itself. Under ICZN, therefore, Coeluroidea and Tyrannosauroidea are only synonyms if you want them to be.

Under phylogenetic nomenclature, Coeluroidea doesn't even exist, since afaik it has never been defined as a clade and even if someone were to define it today, it would be a younger synonym, within this parallel system, of Tyrannosauroidea, assuming someone defined them synonymously, which  doesn't need to be the case (you could define Coeluroidea as a node that may end up as a subclade of the branch-based Tyrannosauroidea, as with Paraves and Eumaniraptora. 

Deinodontoidea is a similar case. It has priority over Tyrannosauroidea in the ICZN system, but doesn't exist in the PhyloCode system.

--Matt Martyniuk

On Apr 12, 2016, at 5:25 AM, Anthony <keenir@hotmail.com> wrote:



> From: mickey_mortimer111@msn.com
> To: dinosaur-l@usc.edu
> Date: Tue, 12 Apr 2016 00:44:18 -0700
> Subject: 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.

Is there precedent for keeping one name at the Genus & Species level, but another name at what was called higher levels?

How is it political correctness?  (are we keeping _Tyrannosauridae_ not because it has priority, but because its better-known and-or is a more popular name?  that doesn't seem any more appealing than political correctness.  (though, if we were being politically correct, wouldn't we rename it in the language of one or more of the tribes who lived where the type specimen of genus _Tyrannosaurus_ was found?))


> 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 Deinodontidae. 

Not sure I understand what you're saying there...  If _Appalachiosaurus_ is outside Tyrannosauridae, but is indistinguishable from part of the Deinodon material, then wouldn't that make a _Deinodontidae_ group even more useful?  (holding the _Tyrannosauridae + _Appalaciosaurus & _Bistahieversor_)