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Re: The Megalania Chronicles
Jason/Jura <firstname.lastname@example.org> wrote:
> This one just came out in PNAS.
> A central role for venom in predation by Varanus komodoensis (Komodo
> Dragon) and the extinct giant Varanus (Megalania) priscus.
Just an update... the paper is now officially out in print form.
> The paper is really neat, and not just because I have a slight bias in
> favour of it (though not as much as Tim :)),
:-) My sole contribution to the work was moral support, as spouse of one of
> I'm not a fan of the continued use of the contentious
> Toxicofera, and I do
> doubt that Megalania was venomous (though it is a neat idea
> to entertain),
I'm skeptical of any clade based predominantly on molecular phylogenetic
evidence. But the claim that _Megalania_ (now sunk into _Varanus_) was "the
largest venomous animal to have ever lived" is certainly a neat idea.
Mosasaurs also fall within the Toxicofera, suggesting that venom glands were
primitive for mosasaurs too (*if* the Toxicofera hypothesis is valid). I'm not
necessarily saying mosasaurs were venomous, but applying phylogenetic
bracketing implies that venom was at least present in their ancestors.
Apparently, the idea of venomous mosasaurs is not new...
This reminded me of reports of a venomous theropod from the Cretaceous of
Mexico. The hypothesis is based on a single tooth.
Given that the tooth in question was only ~ 2cm long, there's little chance of
the theropod (even if venomous) outranking "_Megalania_".
The Late Permian therapsid _Euchambersia_ (Therocephalia) has also been
regarded as venomous, on more solid grounds. The venom-producing glands would
have been held in a recess behind the canine teeth, which were grooved. I
don't know how large _Euchambersia_ was, but a close relative (_Moschorhinus_)
has been said to have "skull dimensions [that] range from those of a large
monitor lizard to those of a lion" (Van Valkenburgh & Jenkins, 2002).