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Re: Venom in Sinornithosaurus

Aw, c'mon! Cobras are cursorial relative to what? Vipers? 

Perhaps I used "cursorial" in an inexact manner here, but on a functional 
level, snakes are _slow_. They require slow prey, or some strategy (e.g., venom 
or ambush) to negate the speed advantage of (e.g.) a rabbit.

As to the selective advantage of poison in weakening resistance, in addition to 
preventing escape, good point, and it fits well w/ an incremental scenario...

I am still however, unaware of any fast 'envenom-aters'.

--- On Thu, 12/24/09, Jura <pristichampsus@yahoo.com> wrote:

> From: Jura <pristichampsus@yahoo.com>
> Subject: Re: Venom in Sinornithosaurus
> To: dinosaur@usc.edu
> Date: Thursday, December 24, 2009, 2:06 PM
> --- On Thu, 12/24/09, don ohmes
> <d_ohmes@yahoo.com>
> wrote:
> > 
> > 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.
> ++++++++++++++++++++++++++++++++++++
> Actually vipers are the only venomous vertebrate group that
> I can think of, that show an association of venom with a
> slow and "sluggish" lifestyle (hmm, I suppose lionfish do
> too, though that's a bit different). The other major
> venomous snake group (Elapidae) is composed of cursorial
> animals. 
> The point of venom is not always to keep prey from getting
> away. One of its main advantages is that it reduces the
> ability of prey to fight back, thus reducing potential
> injury to the predator.
> Jason