Interesting paper which talks about the evolutionary path of snakes. Firstly thought to be closely related to Varanus species due to similarities in teeth and tongue structure. Surprisingly it is lizards like the iguanas which are the ancient ancestors to the venomous snake species of today. The evidence for this hypothesis is the presence of libial glads located in the upper and lower jaw at the base of the teeth. If these ancient lizards did indeed evolve the very first primitive venoms and apparatus for venom delivery then why did it not develop in modern lizard species?. There are only a handful of lizard species considered venomous but none of which are as advanced as the venomous snake species found today.
Kochva E, 1986, The origin of snakes and evolution of the venom apparatus, Toxicon, vol.25, no.1, pp.65-106.
Nice background. The origins of venomous snakes are interesting, but the lead in to this topic was a bit unclear. I am curious about what the similarities are between Veranus and venomous snakes, in terms of tongue structure. Can you elaborate on this?
ReplyDeleteSorry for the late reply Tasmin. So the similarities between Varanus species and snakes in general regarding tongue structure was the way they have adapted to use it as a primary source to locate prey. The tongue picks up scent molecules and is forked so that the animal can determine which direction the scent is coming from. Snakes and monitor lizards also posses and Jacobsons organ located in the roof of the mouth where the scent molecule are deposited then determined by the brain. There wasn't a lot of details in this particular article. I might do a bit of digging and find some more in depth info on the evolution of the forked tongue.Interesting stuff.
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