RE: Brachytrachelopan mesai [was Short-necked dinosaur challenges accepted theory]

[don ohmes <d_ohmes@yahoo.com>]

If you dismiss the physiological objections (i.e.,
blood pressure) to high browsing, it seems to me that
the existence of a sauropod adapted for low browsing
supports the long neck/high browsing hypothesis rather
than challenging it. Maybe this is the "Geraldo"
effect?

--- Tim Williams <twilliams_alpha@hotmail.com> wrote:

> Jaime A. Headden wrote:
> 
> >   My initial comment on the animal is that it's
> not as "upsetting" of any
> >theory as it might be touted as in the press, but
> then that's what gets it 
> >in
> >_Nature_ and popularized.... *Isisaurus* also has a
> fairly short neck, and 
> >it's
> >likely most saltasaurids were short-necked, given
> their smaller size may 
> >have
> >prevented long-necks from being neccessary in any
> sense of forage, feeding
> >enveloped, etc.
> 
> Nevertheless, _Brachytrachelopan_ does seem to have
> an even shorter neck 
> than these short-necked titanosaurs.
> 
> >   The name is rather confusing in an etymological
> standpoint: the Mesa 
> >family's
> >short-necked sheep-shepherd.
> 
> Or "the Mesa family's short-necked shepherd-god".
> 
> ><Interestingly, the cladogram shows _Amphicoelias_
> as a basal diplodocoid -
> >more basal than _Suuwassea_, rebbachisaurids and
> dicraeosaurids (like
> >_Brachytrachelopan_).  This must be based on new
> and undescribed material 
> >of
> >_Amphicoelias_.>
> >
> >   Or a reinterpretation of the known material?
> 
> Could be - but there is not much to go on if only
> the type specimens for 
> _Amphicoelias altus_ and _A. fragillimus_ are used. 
> New (and better) 
> _Amphicoelias_ is known:
> 
> Wilson, J.A. and Smith, M.B. (1996): New remains of
> Amphicoelias Cope 
> (Dinosauria: Sauropoda) from the Upper Jurassic of
> Montana and diplodocoid 
> phylogeny. J. Vert. Paleont. 16 (3, Suppl.): 73A.
> 
> Cheers
> 
> Tim
> 
> 
>