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

[Tim Williams <tijawi@gmail.com>]

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.

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.

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.

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.