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Venom Lineage
A recently published article in the journal Nature suggests that venomous lizards are much more widespread than anyone realised. Furthermore venomous lizards and snakes are in fact descended from a common ancestor that lived about 200 million years ago.
Dr Fry identified the
"prescence of venom toxins in... Iguania... and shows that all lineages possessong toxin-secreting oral glands form a clade, demonstrating a single early origin in lizards and snakesand that Pogona barbata, a relative of Eddie's, retains
"characteristics of the ancestral venom system, namely serial, lobular non-compound venom-secreting glands on both the upper and lower jaws, whereas the advanced snakes and anguimorphs lizards ... ...have more derived venom systems characterised by the loss of the mandibular (lower) or maxillary (upper) glands."
Dr Fry's team of international scientists isolated crotamine — the classic venom of rattlesnakes whose bite can be fatal to humans — in the barbata, but emphasised that the bearded dragon's delivery system is primitive and it is present in such small amounts it would not harm a human.
The paper is worth a read, rather than going on just the snippets above. Also please note that this paper has only just been published and has not yet been responded to.
For more information:
Posted by skitz at November 24, 2005 09:26 AM | Link