Re: dinosaurs did eat grass

[Denver Fowler <df9465@yahoo.co.uk>]

Hmm, on the questions... wait and see. Nothing hugely
exciting, but good stuff all the same.

Anyway, I am not saying that Rebbachisaurs originated
in Europe, but they are present in Europe early when
grasses apparently are not. If we had any evidence for
grass in the British wealden I'd have expected to have
heard or seen something by now. There is an awful lot
of good quality well-studied plant material, worked on
by the team at Manchester.

Denver.



> 
> But these rebbachisaurids and spinosaurids are not
> very much older
> than the ones in north Africa, are they? (Barremian
> vs. Albian?) Is
> our sample size big enough to say that these taxa
> must have originated
> in Europe, or might they have originated in Gondwana
> but left no
> (found) trace of their earliest appearance?
> 
> Furthermore, skull material is not known for the
> European
> rebbachisaurid _Histriasaurus_, is it? Thus it would
> be conceivable
> that, even if rebbachisaurids first split off from
> other diplodocoids
> in Europe, they may not have developed the unique
> jaw morphology
> before they infiltrated Gondwana.
> 
> Come to think of it, rebbachisaurids would have to
> have split off from
> the dicraeosaurid/diplodocid line before the
> Morrison/Tendaguru,
> probably during the Middle Jurassic or at least the
> Oxfordian, so
> we've got a fairly decent ghost lineage here. The
> earliest known
> diplodocimorphs are both Laurasian (Morrison) and
> Gondwanan
> (Tendaguru), so it doesn't seem to me that we have
> any idea which part
> of the globe diplodocimorphs originate from.
> (Although the presence of
> a close relative, _Haplocanthosaurus_, in the
> Morrison might slightly
> favor Laurasian for now, I suppose--but very
> slightly indeed.)
> 
> Who knows?
> --
> Mike Keesey
> The Dinosauricon: http://dino.lm.com
> Parry & Carney: http://parryandcarney.com
> 



                
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