A new study carried out by a group of researchers from South Australia's Flinders University and the University of Alberta in Canada suggests that primitive snakes were probably equally good in two skills— living underground in burrows and swimming in water.

Burrowing and swimming capabilities of ancient snakes

Scientists have always argued about ancient snakes’ swimming and burrowing capabilities. While one camp suggests that snakes evolved their long bodies to be better swimmers, the other camp argues that such long bodies likely helped snakes to be better burrowers.

Last year, a study done by Robert Reisz and his colleagues at the University of Toronto at Mississauga, suggested that snakes most likely evolved in the water and not on land. Researchers arrived at this conclusion after closely examining the fossilized remains of Tetrapdophis amplectus—a snake-like creature that lived about 110 million years ago. Researchers argued that this creature was closely related to aquatic lizards, and was able to evolve a long body for eel-like swimming. Tetrapdophis amplectus was found to have a body that closely resembled those of modern snakes. It also featured four paddle-like limbs and a slender tail. Reisz argued that the slender, short tail and the limbs of Tetrapdophis amplectus are not consistent with features exhibited by modern lizards and burrowing snakes.

Inner ear scans of snake and lizard species

The new study carried out by Australian and Canadian researchers focused on computed tomography scans of the inner ear of about 80 snake and lizard species. These scans also included a scan of the remains of an ancient snake species called Dinilysia. The analysis revealed that the inner ear region of the Dinilysia had striking similarities with some modern-day burrowing snakes as well as semi-aquatic snakes.

According to researchers, the results indicate that ancient snake had good swimming abilities like eels, and they were also fearsome burrowers like worms.

Dinilysia patagonica was a stem snake that existed in the Late Cretaceous period in South America. It grew about 6 –10 feet in length. When the fossil of the snake was first found, researchers performed an x-ray computed tomography to create a digitized endocast of its inner ear.

The results revealed that its inner ear anatomy had three primary part—a big foramen ovale, a large spherical vestibule, and slender semicircular canals.

Alessandro Palci, a researcher at the Flinders University’s biological sciences department, says the elongated bodies of snakes and their flexible skulls are remarkably different from lizards—the closest relatives of snakes. According to Palci, the new study improves researchers’ understanding of how evolution works and confirms that present-day snakes have evolved from being sea-dwelling and land-dwelling creatures.