A 6-meter-long (20-foot) Triassic reptile with a 3-meter-long (10-foot) neck has been puzzling scientists since it was first described in 1952. Paleontologists were unsure as to whether the incredibly long-necked animal lived in water or on land, and whether some similar-looking 1.2-meter (4-foot) animals were related to these 20-foot giants or a different species altogether. Fortunately, a new paper published in the journal Current Biology has been able to clear up the mystery as CT scans of the fossils revealed new evidence.
Named Tanystropheus hydroides, the fossil was once thought to be that of a flying pterosaur, like a pterodactyl. The theory was fueled by the animal’s long hollow “phalange” bones that resemble something that might have supported a wing. However, researchers soon realized their error as it became clear these bones were actually elongated neck bones, similar to those seen in giraffes. Once you put all 14 bones together, it revealed an unusual animal that was 50:50 body to neck. The bones would also have been inflexible as they were reinforced with cervical ribs.
Unusual body type secured, the researchers were still no closer to working out where on Earth this strange creature lived. That was until this new paper employed the help of a CT-scanner to paint a better picture of the reptile’s skull. Retrieved specimens had been crushed, making it difficult to assess how they looked simply using the naked eye, but the scan was able to digitally reassemble them.
The process revealed that the Tanystropheus skull had tell-tale features of a marine animal. It had nostrils on top of its snout much like that of a crocodile, implying it spent some time laying in wait for passing fish and squid-like animals.
Olivier Rieppel, a paleontologist at the Field Museum in Chicago and one of the authors on the paper, wasn’t surprised by the outcome. "That neck doesn't make sense in a terrestrial environment," he said in a statement. "It's just an awkward structure to carry around.”
The Tanystropheus hydroides specimens were found in Switzerland alongside some similar-looking animals that were only 4 feet long. Scientists were again unsure if these other specimens were marine or terrestrial, or if they were a juvenile stage of the larger T. hydroides. They looked for growth rings in the animals’ bones, which revealed there were many, indicating they were adults and not juvenile forms of Tanystropheus, but instead a completely different species called T. longobardicus.
"I've been studying Tanystropheus for over thirty years,” said Rieppel, “so it's extremely satisfying to see these creatures demystified.”