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

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

Mickey Mortimer <mickey_mortimer111@msn.com> wrote:

> It's
>  happened before without incident- Sereno proposed and defined
> Torvosauroidea and Oviraptoroidea, but later changed these to
> Spinosauroidea and Caenagnathoidea respectively based on ICZN rules.
> The former was then changed to Megalosauroidea.  As for Deinodon being a
>  nomen dubium, that's just been an assumption for decades.  Even if
> further study convinced me it is undiagnostic, do you really want such a
>  subjective determination to be the basis for nomenclature?

Frankly, yes.  Subjective it may be, but arbitrary it is not.  The
'subjective' determination is based on scientific expertise and
experience.  In my view, that trumps the arbitrary rules of the ICZN,
which only avers that the family that was named first gets priority.

When defining a clade with the eponymous genus as the specifier, it's
best to use a genus that is actually valid.  I know 'validity' is
sometimes in the eye of the beholder.  But for _Deinodon_, I don't
know of anyone who thinks it's valid.  So I can't see any reason why
Deinodontoidea should supplant Tyrannosauroidea.

I understand your Spinosauroidea/Torvosauroidea/Megalosauroidea
example... yes, Megalosauroidea eventually won out.  After all, it has
priority.  Recent studies support _Megalosaurus_ as a valid genus, so
I've got no problem with clade Megalosauroidea.

Of course, we could just have names like Megalosauria, Tyrannosauria,
Oviraptoriformes, Caenagnathia, Caenagnathiformes, etc (and avoid the
suffix -oidea), which would bypass ICZN altogether.

> There
>  actually is populist anarchy for clades not governed by the ICZN.  Is
> the ceratosaur+tetanurine clade Neotheropoda or Averostra?  The
> carnosaur+coelurosaur clade Avetheropoda or Neotetanurae?  Is the clade
> closer to modern birds than dromaeosaurids Avialae or Averaptora?  Is
> Aves crown birds or the clade of them plus Archaeopteryx?  Is Ornithurae
>  taxa closer to living birds than Archaeopteryx, the
> hesperornithine+crown group, or something involving pygostyle
> development that is located around Ornithuromorpha?  These are reasons
> why we need the Phylocode to be enacted, so that it can have to power to
>  settle these disputes.

Yep, I'm aware there's no consensus regarding the 'standard'
definition of many clades.  Aves is a famous/infamous example.  I
agree that PhyloCode should solve these sorts of problems.  But having
coordinated family-level taxa governed by ICZN rules just adds an
additional (and unnecessary) layer of complication.