Re: Vampire-osaurs?

[Amtoine Grant <ajgrant@eastlink.ca>]

> Well, I am not fully up to date on the morphology of the psittacosaur
> quills, but it seems unlikely that they would contain venom tubes.  As 
> far
> as I know, they were very long and likely flexible, which does not 
> make a
> very good venom injection mechanism (would tend to bend and not stab). 
>  More
> to the point, however, they would have to be grooved or hollow to 
> inject a
> toxin, which may or may not be evident from the specimens.

IF it needed to be injected. I'm pretty sure there are frogs/toads that 
can secret a poisonous substance when the need arises.

> More generally speaking, though, I would take some care in suggesting 
> that
> dinosaurs were likely to be poisonous or venomous because extant 
> reptiles
> are.  The only venomous extant reptiles fall within the helodermids 
> (Gila
> Monster and beaded lizard) and snakes, which are rather related, so 
> venom
> use is only common in one clade of lepidosaurs.  I believe (can someone
> confirm?) that there are some poisonous birds, but only a few out of 
> the
> some 10,000 species.  Thus, extant archosaurs are not prone to be 
> poison
> users, and none are venomous.  Overall, reptiles get a reputation as 
> toxin
> users only because snakes are prone to evolving venom use.  Their 
> unique
> ecology and physiology plays a major role in this.

Also, komodo dragons are technically poisonous.  And I believe that sea 
snakes have some of the most toxic venom among snakes. They'd rather 
not go chasing their prey all through the water until the venom takes 
full effect, go following it's scent through the water and/or give 
another predator a free meal. Mosa/Plio/Plesio, anybody? hehehe . . .