[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Venom in Sinornithosaurus



> > More than just 'a few' lizard species would have to
> have become extinct.
> > It's been estimated that up to 100 lizard species
> world-wide might be
> > venomous to some degree, based on the varanid and
> iguanian species that
> > venom glands have been identified in so far.

Ok, then I'll propose a more restrictive extinction event:

Suppose all snakes go extinct except for the non venomous Corn Snake family.
Do you then conclude despite finding fossils with fangs, that the snakes were 
non-poisonous, as there must be some other function for the fangs?

Thats essentially what happened with theropods/archosaurs - very restrictive 
extinctions. Only neoornithes/crocs survived to our current age and radiated - 
with the crocs not doing nearly as much radiation.
Archosaurs today are not that *diverse* (depending on your measure, yes I know 
birds as a group have one of the highest species numbers).
Most archosaur lineages are extinct.
Most mammals are non-venomous, so if you get rid of most mammals, it is likely 
that you will have gotten rid of all venomous mammals, the same may have been 
true for Archosaurs.

Yes, I know - if only corn snakes were around, there would be no evidence in 
extant animals for venom, and we shouldn't assume earlier snakes had venom - 
fine.

But if a fossil is found suggesting venom, we shouldn't look at extant 
relatives, and take the absence of venomous as indicating the fossil wasn't 
venomous.

That said, I don't think this particular fossil has any strong indications of 
being from something venomous - I just don't buy the birds aren't venomous, so 
to say a dinosaur was venomous is an extraordinary claim.
I simply view it as an unsupported claim at this time.