A recent discovery of a 110-million-year-old fossilized snake with four feet may shed some light on how modern snakes evolved from their prehistoric ancestors. David Martill, a paleobiologist at the University of Portsmouth, first saw the snake at an exhibit in the Museum Solnhofen in Germany.
After further examining the fossilized snake, Martill, along with German paleontologist Helmut Tischlinger and Nick Longrich from the University of Bath’s Milner Centre for Evolution, dubbed the four-legged serpent Tetrapodophis amplectus.
According to reports by the International Business Times, the specimen measured 20 centimeters in length and its head was about the size of a human fingernail. The snake also had two front legs and two hind legs, and all four limbs measured a little over one centimeter. The snake also seemed to have feet-like appendages attached to its legs. Longrich and his colleagues speculated that the feet most likely did not enhance mobility but were used for grasping prey or perhaps even mates.
“The hands and feet are very specialized for grasping. So when snakes stopped walking and started slithering, the legs didn’t just become useless little vestiges — they started using them for something else. We’re not entirely sure what that would be, but they may have been used for grasping prey, or perhaps mates.”
The discovery of Tetrapodophis amplectus further strengthens the theory that modern snakes once evolved from lizards, and that over time, these lizards slowly elongated their bodies and lost their limbs.
National Geographic reports that this particular specimen was a hunter and most likely preyed on lizards, fish, and salamanders. Like many modern boas and pythons, this snake also seemed to use constriction as the primary means of subduing and killing its prey.
Another troubling find made by scientists was that this four-legged snake appeared after more ancient ancestral snakes such as Eophis, Parviraptor, and Diablophis. However, it is interesting to note that these three snakes that preceded Tetrapodophis all had two limbs, not four. According to Martill, these four different species of snake most likely coexisted at some point in time, each with its own distinct evolutionary lineage, and each equally likely to have evolved into modern day snakes.
“At any one time in the Cretaceous, chances are you’ve got ten, twenty, maybe thirty species [of early snakes], all going off on their own evolutionary paths. There would be a whole bunch of very snake-like lizards, all with the potential to become today’s snakes.”
Regardless of where this newly discovered four-limb snake places in the snake family tree, it is certainly a significant piece to the puzzle in determining the evolutionary relationships between ancient lizards and modern day serpents.
[Photo Credit: Dave Martill]