(CNN)For more than a hundred years, the fossil of the Tanystropheus has puzzled scientists.
The strange reptile -- resembling a real-life Loch Ness Monster or a prehistoric crocodile crossed with a giraffe -- was first described in 1852 and first reconstructed in 1973.
Paleontologists have long known that the species once lived in Switzerland's Monte San Giorgio basin during the Middle Triassic period (about 242 million years ago). They also knew the bizarre-looking 20-foot creature had a remarkably long neck, which at 10 feet long was half of its entire length.
But the remaining details surrounding the Tanystropheus remained fuzzy and have been much debated. Did these animals live on land or in the water? What did their young look like? And how did they interact with the other species in their environment? No one knew -- until now.
Scientists used computed tomography (CT) scan technology to digitally reconstruct the crushed skulls of the fossils, which revealed evidence that these reptiles were water-dwelling, according to new research published today in Current Biology.
"For those people who are interested in Triassic reptiles, it's always been not only an iconic fossil but also a matter of dispute and discussion," said Olivier Rieppel, a paleontologist at the Field Museum in Chicago and one of the study's authors.
"I've been studying Tanystropheus for over 30 years, so it's extremely satisfying to see these creatures demystified."
The digitally reassembled fossils show that the Tanystropheus' skull anatomy and nostril placement had the characteristics of an aquatic animal. Researchers also found evidence that the Tanystropheus was an aquatic "ambush predator" that likely used its long, slender neck to allow it to approach unknowing prey.
"That long neck wasn't very flexible, it only had 13 vertebrae and it had ribs in it that further constrained mobility," Rieppel explained. "But our study shows that this strange anatomy was much more adaptive and versatile than we had thought before."
A second mystery solved
Scientists were also able to clear up questions surrounding different forms of these animals -- one smaller and one larger -- whose fossils are found in the same area of modern-day Switzerland.