RE: Inglourious New Papers

[Tim Williams <tijawi@yahoo.com>]

Michael Mortimer <mickey_mortimer111@msn.com> wrote:


> Metriacanthosaurus cannot be a sinraptorid according to the
> ICZN, as Metriacanthosauridae (1988) was named before
> Sinraptoridae (1993/1994).  I'm sure the reply is that
> "Sinraptoridae is phylogenetically defined", 


Dead right.  Sinraptoridae IS phylogenetically defined - which is the very 
reason why _Metriacanthosaurus_ belongs in this clade.  That should count for 
something.


The name Sinraptoridae was originally erected (1993) to include two  closely 
related genera: _Sinraptor_ and _Yangchuanosaurus_.  Sinraptoridae was 
subsequently (1997) defined as a stem-based clade (_Sinraptor_ but not 
_Allosaurus_; later emendations added other external specifiers).  Recent 
phylogenetic analyses have recovered _Lourinhanosaurus_ and 
_Metriacanthosaurus_ as falling inside this clade.  _Metriacanthosaurus_ is 
based on fragmentary material, whereas_Sinraptor_ is based on an excellent 
skeleton; so I can't see any good reason to replace Sinraptoridae with 
Metriacanthosauridae.  


Let's say we do go ahead and change the name from Sinraptoridae to 
Metricanthosauridae.  Let's also say another analysis finds that 
_Metriacanthosaurus_ falls outside the sinraptorid clade (as a basal 
allosauroid, for example) - you know how these fragmentary taxa tend to bounce 
around in phylogeny.  Then we have to go back and start calling the clade 
Sinraptoridae all over again, all because of the position of one very poorly 
known genus (_Metriacanthosaurus_).


>From the point of view of nomenclatural stability, re-naming Sinraptoridae 
>seems counterproductive.  You're advocating re-naming the clade solely because 
>of the historical quirk that somebody (G. Paul) once erected a family called 
>Metriacanthosauridae.


To use an analogous example... What if _Ornithodesmus_ is referred to 
Troodontidae?  Using your argument, does this mean that we have to re-name this 
clade Ornithodesmidae, because Ornithodesmidae was named before Troodontidae 
(1913 vs 1924)


> but Phylocode
> isn't implemented until 1-1-200x.  Surely we should
> follow the ICZN at least until then, and if we're free to
> ignore it now, why not just ignore it next time a priority
> issue comes up which we don't like? 


But Mickey, it's always come down to personal preference.  We use 
Tyrannosauridae (Osborn 1905) rather than Deinodontidae (Cope 1866), even 
though the latter family was in usage for nearly a 100 years, and _Deinodon_ is 
clearly a tyrannosaurid.  Tyrannosauridae is preferred over Deinodontidae, 
because _Deinodon_ is considered a nomen dubium.  But _Ceratops_ is almost 
universally regarded as a nomen dubium too, and we still use Ceratopsidae 
(Marsh 1890) in preference to Centrosauridae (Lambe 1915).


So if the ICZN rules are inconsistently applied, why start renaming 
family-level clades purely on the basis of what year they were named?  It only 
adds to the taxonomic 'churn'.  


> On a more positive note, the paper looks extremely
> interesting, as Benson's been doing some great work.


Can't disagree with that!

:-)


Cheers

Tim