What are you more afraid of: snakes or lizards? A lot of people are much more comfortable with lizards, despite their origins.
A fact that might be surprising to people who feel that way is that the ancestors of snakes are lizards. Scientists are still trying to figure out why those ancient lizards evolved into snakes.
Four-Legged Snakes
It's a generally accepted fact that snakes evolved from lizards, but how they lost their legs is still controversial. Luckily, scientists recently discovered a fossil of a four‑legged snake that could give us some more clues.
Yes, you read that right, "four-legged snake." Some of the reasons why the scientists classified it as snake rather than a lizard are: the skeleton has a long body, and not just a long tail; the jaw bones and teeth are snake‑like; and the skeleton shows hints that the animal had a single row of belly scales, which lizards don't have.
These Hands Are For Prey
One really interesting observation the scientists made is that the hands and feet were capable of grasping things. The observation shows when snakes started slithering, they used their legs for something other than walking.
One thought was instead of just letting them hang uselessly on their bodies, the snakes may have used their "hands" and "feet" to grasp prey or mates.
Losing their legs was an adaptation to living underground in burrows. Extra limbs would just get in the way if you're spending your life slithering through tunnels.
Sources And Further Reading:
- University of Portsmouth. "Four-legged snake fossil found." ScienceDaily. July 23, 2015. (accessed August 24, 2017)
- Dave Martill et al. A four-legged snake from the Early Cretaceous of Gondwana. Science, July 2015 DOI: 10.1126/science.aac5672
- Kennedy, Merrit. "How Snakes Lost Their Legs." NPR: The Two-Way. October 20, 2016. Accessed August 24, 2017.
