Re: [dinosaur] Plateosaurus species

[Tim Williams <tijawi@gmail.com>]

Mickey Mortimer <mickey_mortimer111@msn.com> wrote:

> I'm actually curious about this as well.  The ICZN designated trossingensis 
> the type species, but didn't explicitly grant it any priority over other 
> species names.  So sure there are the
> possibilities of viewing engelhardti as indeterminate at the species level or 
> above, or viewing it as a separate diagnosable species than P. trossingensis.

It's my understanding that _P. engelhardti_ is currently regarded as a
nomen dubium.  As such, it should have no taxonomic standing.

>  But if someone does the latter, are they allowed to create a new genus name 
> for engelhardti like 'Euplateosaurus' since Plateosaurus is based on 
> trossingensis now?

I'd say yes.  If the type material of _P. engelhardti_ is demonstrated
not to belong in the same genus as _Plateosaurus trossingensis_ (or in
any other genus), but is diagnostic at genus level - then
_engelhardti_ warrants its own genus.  (Not that I think this will
ever happen...)

> Or, if somebody thinks the species are synonymous, should they call the 
> resulting taxon Plateosaurus engelhardti because engelhardti still has 
> priority?

So in the event that _P. trossingensis_ and _P. engelhardti_ are
demonstrated to be conspecific.... this is a tricky one.  My
interpretation is that because _P. trossingensis_ was declared by fiat
to be the type species, and that _P. engelhardti was specifically set
aside as type species in the same decision, that _P. trossingensis_
would therefore have priority over _P. engelhardti_.

>  It's like how the type species of Tarbosaurus is T. efremovi, but if 
> Tyrannosaurus bataar is synonymous like most everyone thinks, it's called 
> Tarbosaurus bataar because that species
> was named first.

The _Tarbosaurus_ example would seem to offer a precedent - but again,
I think the fact that the ICZN decision explicitly sets aside all
previous fixations of type species for _Plateosaurus_ means that _P.
trossingensis_ now always comes out on top, no matter where _P.
engelhardti_ ends up taxonomically.