Venomous Lizards

[Sdaji]

I think your twisting his words there Sdaji, I've read the paper and the conclusion isn't that Varanids or Agamids use the venom mechanism, simply that venom may have evolved earlier in squamate evolution then was previously hypothesised. The paper is more of an Evolutionary Biology paper then a Toxinology or animal behaviour paper.

He has been going around for years now saying that they use the venom to kill prey. There is no surprise at all if you find enzymes common to rattlesnakes and goannas - as I said, humans have enzymes in their saliva which are common to both goannas and rattlesnakes (and every other reptile). All known life is related, that's not new information. It has been known for a very long time that snakes evolved from lizards (in fact, snakes are a type of lizard). There's nothing at all new about that knowledge either.

If it was merely a case of determining relationships, no one would care, that sort of research is easy to carry out using analysis of heaps of different characteristics. What he is doing is making everyone say "Wow!" by misrepresenting information, in a (successful!) attempt to gain attention and funding.

What he is suggesting is like saying "Wow, if you look at the wings of birds and bats you can see that they both have common features, such as five digits! They must have evolved only once, they are so similar!". This is complete nonsense and it is decades, probably over a century since anyone has tried to make that suggestion. It may be possible that one common ancestor of all snakes was venomous, and evolution 'reinvented' it several separate times in snakes (this would be the equivalent of several different groups of snakes independantly evolving to have legs again). If that's the case it would be quite interesting. What he has said about all iguanas, dragons and colubrids being venomous is just plain silly, and is a deliberate misrepresentation of the facts in order to achieve his goals (I must admit, he has been quite successful in doing so!).

 

[slacker]

Fair points.

I've some belief in his research, however. I could be misguided, but I'm not a scientist and so I put trust in those that are, rightly or wrongly.

My main reason for belief in his research is because of the behaviour of stegonotus cucullatus, and some symptoms I received after being bitten many times by them.

It is my belief (although I admit to still retaining doubts) that the "non-venomous" Stegonotus cucullatus are in fact very mildly venomous.

I owned a pair of these for a time in the past and received many bites. All bites I received were washed thoroughly shortly afterwards. Many of the bites subsequently showed symptoms, possibly of a very mild envenomation, possibly of infection. Said bites resulted in redness, mild blistering, itching, stinging and burning. Symptoms passed over about a week and none of them were anything more than a mild irritation.

At the same time, my then partner received bites from the same snakes. Her bites were not washed afterwards and she did not develop any symptoms at all.

This, of course, could be due to bacteria on the teeth of the animals, or in the saliva. My main reason for suspecting venom was their biting behaviour. Rather than striking in a defensive way typical of pythons, they would instead force their jaws over an area and chew heavily. I think this to be (and I'm by no means an expert, but it is my supposition) behaviourly indicative of a "rear-fang" venom delivery system.

With all of the above said, I'm probably wrong and it was probably bacteria, but it most definitely makes me wonder!

 

[Tristis]

ive found monitor bites to sting, where as other lizards dont

 

[callith]

very interesting, thanks