Tuesday, 22 December 2009

'Venomous' dinosaur!

Well I suppose it shouldn't come as a great surprise that a dinosaur might have been venomous; after all, many reptiles, eg komodo dragons, use venom to subdue their prey. Bit it's a nice extra snippet of information to file away. The Beeb tells us about a paper in the Proceedings of the National Academy of Sciences journal.

In the context of fangs, snakes fall into two categories; those with their fangs at the front, like cobras, rattlesnakes and mambas, which kill their prey by poisoning them, and those with their fangs at the back, like pythons and anacondas, which kill their prey primarily by constriction, though they do also have venom.

According to the paper

Rear-fanged snakes are considered less dangerous than other venomous snakes.

The fangs in these snakes do not inject venom, but instead channel the poison along a groove on the outer surface of teeth that pierce their prey's flesh.

Sinornithosaurus had upper teeth that were similarly long, grooved and fang-like.

Just as a little aside here, I was at a talk by a snake venom expert a few years ago, in which he dispelled a myth about snakes, though like all good myths, it continues to propogate around the world.

When he analysed the venom of venomous and 'non-venomous' snakes, he found it was essentially the same. All snakes use basically the same venom. The big difference is that 'non-venomous' snakes inject it using fangs at the rear of their mouths, so don't generally manage to inject very much. This was tragically demonstrated in the case of a boy in the US whose parents had given him a 'non-venomous' snake as a pet. The snake bit him and managed to inject a lethal dose of its poison.

So now you know! I didn't know the bit about the rear fangs being grooved rather than hollow.

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