[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

Reminds me of Segnosaurs, replaced by unpronounceable Therizinosaurs.. just for a question of date..
Not to mention the fate of 'Syntarsus' kayentakae

Le 12/04/2016 18:14, Jocelyn Falconnet a écrit :
If we have to forget names based on nomina dubia... what about
ceratopsians and other Ceratops-derived names ?

(I don't even want to elaborate on this case, in fact, knowing I will
surely be executed on the public square in the few minutes following
this mail...)


2016-04-12 9:44 GMT+02:00 Mickey Mortimer <mickey_mortimer111@msn.com>:
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 Deinodontidae.

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
<div id="DDB4FAA8-2DD7-40BB-A1B8-4E2AA1F9FDF2"><br />
<table style="border-top: 1px solid #aaabb6;">
         <td style="width: 55px; padding-top: 13px;"><a 
 " target="_blank"><img 
 " /></a></td>
                 <td style="width: 470px; padding-top: 15px; color: #41424e; font-size: 13px; font-family: Arial, Helvetica, sans-serif; line-height: 
18px;">Virus-free. <a 
 " target="_blank" style="color: #4453ea;">www.avast.com</a>
</table><a href="#DDB4FAA8-2DD7-40BB-A1B8-4E2AA1F9FDF2" width="1"