Snakebite science
30 July 2008
Scientists are fang-ful to have uncoiled the secret behind snakes' dental development. Fearsome fangs moved to the front of snakes' mouths for striking success. Antenna sinks its teeth into the science...
This research was published in the journal Nature on 30 July 2008.
This research was published in the journal Nature on 30 July 2008.
Most snakes use venomous fangs to kill their prey.
Image: Freek Vonk
Cobras' and vipers' fangs are at the front of their jaws - like our canine teeth. Other snakes hide their venomous teeth at the back of their mouths.
This brown tree snakes has fangs hidden away at the back of its mouth.
Image: Freek Vonk
Scientists were puzzled how snakes evolved such differing dentition.
They felt uneasy with the idea that front and back fangs arose independently - snake fangs are complex structures unlikely to have evolved several times.
Cobras and vipers strike bite using their front fangs.
Image: Nature's Images / Science Photo Library
To get to the root of serpents' dental differences, experts followed fang development in the embryos of eight snake species.
They found that in all species fangs grow from a special area at the back of the upper jaw. Amazingly, front fangs move forward as the embryo develops.
Watching embryos develop can tell us a lot about evolution.
Image: Freek Vonk
So what does this tell us about snake evolution?
'Early in their history, snakes fangs developed at the back of their mouths, separate from the rest of their teeth. This uncoupling made it possible for the range of snake fangs we see today to evolve.' Freek Vonk, snake expert
Freek Vonk, snake expert, Leiden University, the Netherlands.
Image: Freek Vonk
Why did snakes evolve front and back fangs?
'With fangs at the back of the mouth the snake has to chew venom into its prey. This isn't good for tackling dangerous prey that can fight back, so most of these snakes feed on small animals like frogs and lizards. Snakes with front fangs inject the venom and wait for their prey to die at a safe distance. This means they can feed on larger, more dangerous prey.' Freek Vonk
Image: Freek Vonk
'This is a very exciting study that fills a major knowledge gap - how the unspecialised teeth of early snakes evolved into the sophisticated chemical weapon system we see in venomous snakes today.' Wolfgang Wuster, venomous snake expert
Wolfgang Wuster, venomous snake expert, Bangor University.
Image: Wolfgang Wuster