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RE: Velociraptor scavenged azhdarchid pterosaur



While I would like to echo Dann's comments regarding assumptions of diet in a 
"typical herbivore" such as *Protoceratops andrewsi*, I'd like to note that the 
general arguments for rendering it a herbivore are both traditional and 
compelling. There really isn't that much that tells us that protoceratopsids 
like *andrewsi* _didn't_ dominate their diet with plants of some sort. I _like_ 
the idea of a omnivore for it, but the reasoning here is actually pretty weak 
as it is based largely on the invocation of not assuming diet due to plasticity 
in diet of living so-called "herbivores," especially pigs and ruminants.

  Just as we should never assume a *Tyrannosaurus rex* is not a strict 
carnivore (and few scientists have done so), we should not assume any typical 
"herbivore" is one, including hadrosaurids. But just as with hadrosaurids, 
there are more compelling reasons to claim they were primarily herbivores that 
no matter how much of their diet was sprinkled with eggs or grubs or small 
multituberculates, a Djadokhtan protoceratopsid probably _did_ prefer plants to 
meat. And just as a tyrannosaur wouldn't turn its nose down to a free, weakly 
guarded carcass, I doubt a Djadokhtan protoceratopsid would turn its beak down 
at a free egg or carcass. There's a lot to say on the issue of any consumer to 
not get shoe-horned into strict herbivory or strict carnivory, but also not to 
presume that omnivory, if possible, was likely and that the animal would be a 
generalist.

  That's all ... for now.

Cheers,

  Jaime A. Headden
  The Bite Stuff (site v2)
  http://qilong.wordpress.com/

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)


"Ever since man first left his cave and met a stranger with a
different language and a new way of looking at things, the human race
has had a dream: to kill him, so we don't have to learn his language or
his new way of looking at things." --- Zapp Brannigan (Beast With a Billion 
Backs)


----------------------------------------
> Date: Tue, 6 Mar 2012 11:16:10 +1100
> From: dannj@alphalink.com.au
> To: dinosaur@usc.edu
> Subject: Re: Velociraptor scavenged azhdarchid pterosaur
>
> On Tue, Mar 6th, 2012 at 9:54 AM, Tim Williams <tijawi@gmail.com> wrote:
>
> > Henrique Niza <drdinopt@gmail.com> wrote:
> >
> > > I think it is far reasonable to assume, considering the difference in
> > > body size between the two specimens preserved, that the Protoceratops
> > > was the one attacking the Velociraptor and not the other way around.
> >
> >
> > I disagree. When a carnivore like _Velociraptor_ is preserved locked
> > in combat with a herbivore like _Protoceratops_... I tend to think
> > that the carnivore might be the aggressor here. After all, this *is*
> > _Velociraptor_.
>
> Why is it automatically assumed that protoceratops was a herbivore? Surely 
> the old days of the
> theropod=carnivore / non-theropod=herbivore dichotomy are long behind us. I 
> don't see any
> reason to discount omnivory amongst ceratopsians in general (even if most 
> carcasses were
> scavenged rather than actively taken down).
>
> The idea that dromaeosaurs were hypercarnivores is surely also an assumption. 
> They may of just
> as well had a broader diet similar to extant canids, for which plant matter 
> can form a considerable
> part of the diet. It doesn't take any obvious dental specialisations to 
> swallow the occasional bit of
> fruit or fungus.
>
> > Why would the _Velociraptor_ get too close to the _Protoceratops_...
> > if not for the obvious reason?
>
> Nest robbing comes to mind. A Velociraptor caught in the act might earn the 
> ire of the egg layer.
> Killing and eating the intruder might just be a beneficial biproduct of nest 
> defense.
>
> --
> _____________________________________________________________
>
> Dann Pigdon
> Spatial Data Analyst Australian Dinosaurs
> Melbourne, Australia http://home.alphalink.com.au/~dannj
> _____________________________________________________________
>