Re: Venom in Sinornithosaurus

[don ohmes <d_ohmes@yahoo.com>]

--- On Wed, 12/23/09, Augusto Haro <augustoharo@gmail.com> wrote:

> Anyway, I think that if we consider
> dubious whether the roots are
> exposed or not, I suppose CT scanning may help settling the
> question
> (whether or not the alveoli are partially empty, as most
> suppose). It
> may lead to some short communication I guess, perhaps
> including a
> reestudy of the presumed recess for the gland, which has
> been
> considered by some as an artifact...
> Perhaps somebody may be arranging things to do this by
> now...

I donât claim the following has any scientific bearing on the paper under 
discussion, except perhaps to underline the extraordinary nature of claims of a 
venom system in an animal of this bodystyle. 

Assuming bipedal bodystyles can be shown in general to be associated w/ 
cursorial lifestyles; and that predatory envenomation strategies, and the 
presence of venom in vertebrates generally, is associated with slowness of 
locomotion* -- It is not obvious what combination of lifestyle and environment 
would be likely to elicit cursorial locomotion and a venom system in a predator 
simultaneously. It also seems intuitively unlikely that a fit cursorial 
predator would evolve an effective venom system, at least not w/out some loss 
of locomotive fitness. 

General questions: We know that dinosaurs are basally bipedal, and that 
herbivorous dinosaur lifestyles are associated w/ massive bodysize**; were 
there any slow carnivorous dinosaurs that could be assumed to prey on small 
animals, and therefore serve as logical candidates to evolve a predacious venom 
system? What incremental evo-scenario resulting in a venom system is possible 
when the prey animals are volant and must therefore die almost instantly to 
convey any advantage to the predator?

*corrections to basic assumptions appreciated.
**and therefore a high inherent resistance to venoms generally, excepting 
perhaps hypothetical bacterial symbionts...