Re: Defunct genera and _Pekinosaurus galtoni_ (was Re: Suchomimus' forcula)

["Timothy Williams" <twilliams_alpha@hotmail.com>]

Dinogeorge@aol.com wrote:

> E.g., lions and tigers are skeletally indistinguishable (any putative
> differences are swamped by individual variation within each species) but
> they're definitely different species. There should be some way to take
> temporal (stratigraphic) and spatial (locality) distribution into account 
> in
> describing species in addition to morphology, but so far our data are not 
> up to the job.

Yep, that's the rub.  Bare bones don't mate and reproduce like real live 
lions and tigers do.  The best way is to play it safe.  When the skeletal 
material of several individuals is consistent and within the morphometric 
range of a single species, then it's perhaps best to only recognise a single 
species, even if that species has a wide stratigraphic and geographic 
distribution.

If this was ruthlessly applied to all dino species, it would spell trouble 
for a lot of sauropod taxa.  _Apatosaurus ajax_ and _A. excelsus_ could 
probably be lumped into a single species - is there a single anatomical 
character that can be used to separate these stratigraphically separate 
species?  Simple overall body size doesn't count.  (Ditto for _Diplodocus 
longus_ vs _D. carnegiei_, _Camarasaurus supremus_ vs _C. grandis_).  It's 
"lumping" for sure, but it beats scrambling to find diagnoses to justify 
upholding species that are uncomfortably close to related species.


Tim



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