Prehistoric fossil mystery solved thanks to help from Field Museum researchers

CHICAGO -- A prehistoric fossil mystery has been solved with the help of a researcher at the Field Museum.

The 20-foot long reptile was discovered in 1852. Ever since then, scientists have been trying to figure out if the creature lived on land or in water.

A new paper just published claims to prove that the creature, in fact, lived in the water. It's described as a stubby crocodile with a "very, very long neck."

At one point, the fossil called Tanystropheus, was thought to be a flying pterosaur, like a pterodactyl, according to paleontologists. Scientists thought the long, hollow bones found with the fossil were phalanges in the finger that supported the wing

Later, they say they figured out that those pieces were elongated neck bones and that the creature was a 20-foot long reptile with a 10-foot neck that was three times the size of its torso.

At the time scientists still weren't sure if it lived on land or in the water, until now.

Researchers say they used CT scans of the fossil's crushed skulls and digitally reassembled it, discovering evidence that told a story of a water-dwelling animal.

"I've been studying Tanystropheus for over thirty years, so it's extremely satisfying to see these creatures demystified," says Olivier Rieppel, a paleontologist at the Field Museum in Chicago and one of the authors of a new paper in Current Biology detailing the discovery.

Tanystropheus lived 242 million years ago, during the middle Triassic when dinosaurs on land were just starting to emerge, and the sea was ruled by giant reptiles, scientists say.

"Tanystropheus looked like a stubby crocodile with a very, very long neck," says Rieppel. "To clarify its taxonomy is an important first step to understanding that group and its evolution."