Evolution in Action

The venom injection system in snakes is both complex and sophisticated. As we have wondered with many other traits, such as insect flight, how did this intricate system evolve?

“Modern venomous snakes have tube-like fangs that inject poison directly into their victims, helping them to kill prey without a struggle.” It has been hypothesized that these hollow fangs evolved from a set of grooved fangs. The developmental process of modern venomous fangs, which change shape as they grow in the snake’s mouth, supports this. The fangs begin with an open groove, and then break through the gum as a sealed tube. These syringe-like fangs are seen in the oldest snake fossil records, up to 20 million years ago. So how did this system develop?

Jonathan Mitchell at the University of Chicago in Illinois has been given a lead to the early evolution of venomous fangs. The Uatchitodon, a reptile that existed approximately 200 million years ago and is only known from its teeth, has been the source of this lead. At one research site, 14 specimens were found with grooved teeth. At a second site, 26 were found with fully developed tubes. These findings mimic what is observed with fang development in modern snakes. However, many questions still remain and further finding are need to support this theory. For example, herpetologist Wolfgang Wüster at Bangor University, UK says that “finding Uatchitodon jaws would be important, to check whether specimens with hollow fangs — but not those with grooved teeth — had compressor muscles that could squirt venom into prey.”

You can check out the article here.

Jen Kodela