Re: Venom in Sinornithosaurus

[don ohmes <d_ohmes@yahoo.com>]

Well, there is the digestive angle... 

--- On Fri, 12/25/09, Mike Habib <habib@jhmi.edu> wrote:

> From: Mike Habib <habib@jhmi.edu>
> Subject: Re: Venom in Sinornithosaurus
> To: drakeducaine@yahoo.com
> Cc: dinosaur@usc.edu
> Date: Friday, December 25, 2009, 1:17 PM
> 
> On Dec 25, 2009, at 12:32 AM, Michelle Pinsdorf wrote:
> 
> > To your credit, most people, especially in the pet
> trade, would say most colubrids are not venomous. As far as
> I know corns aren't venomous at all, anyway. But the venom
> that Thamnophis species produce is literally chewed into
> prey, they really have to gnaw on you to get it in, and even
> then only a handful of people experience a reaction to it. I
> would think a neurotoxin that mild wouldn't do anything much
> to kill prey, but serve better to disable it or reduce
> struggling while being swallowed.
> 
> Rear-fanged colubrids are actually quite widespread, both
> phylogenetically and geographically.  Only a handful
> have venom that is medically significant to humans, but the
> few that do really pack a wallop (twig snake, boomslang, a
> few others).  Interestingly, despite the convergent
> nature of opisthoglyphy in the various venomous colubrid
> groups, many (most?) of them seem to share a tendency to
> utilize blood vessel wall damage and anticoagulant effects
> as a primary attack form.  Very few, if any, are
> substantially neurotoxic.  Human fatalities from
> boomslang bites, for example, occur as a result of massive
> internal bleeding.  Even those species that have little
> effect on humans and are not considered "medically
> significant" seem to produce somewhat accelerated bleeding
> from the bit wound.  To the best of my knowledge, no
> one has determined a functional, phylogenetic, or
> developmental underpinning to this trend (but someone else
> here may know something I don't).
> 
> Cheers,
> 
> --Mike Habib
> 
> 
> Michael Habib
> Assistant Professor of Biology
> Chatham University
> Woodland Road, Pittsburgh PA  15232
> Buhl Hall, Room 226A
> mhabib@chatha

> (443) 280-0181
> 
> 
> 
>