Nearly 250 million years ago, a very unusual reptile patrolled the shores and ridges of the Triassic Alps. Called Tanystropheus, it had a tooth head and a body that reflected that of modern monitor lizards. But between her struts a horizontal, giraffe-like neck.
The question of how this 20-foot creature that has a nine-foot neck has been used by paleontologists for more than 100 years, and it is seen as “one of the most baffling animals that ever lived,” said Stephan Spiekman, a paleontologist at the University of Zurich, Switzerland. ‘How could this animal even breathe or swallow? And then there’s the evolutionary question: Why on earth did this animal develop this ridiculously long neck? “
But research published last week in Current Biology, including a new reconstruction of his skull, shows evidence that his body was set up for an aquatic hunting strategy and that the creature came in two varieties: regular and miniature.
Tanystropheus was originally described in the 1850s, based on a few public bones. It wasn’t until the 1930s, when more complete fossils emerged from Monte San Giorgio in Switzerland, that scientists knew they were looking at cervical vertebrae of an alien reptile whose way of life they could not invent.
It took decades until paleontologist Karl Tschanz in 1988 found that ribs collapsed under the cervical vertebrae, forming a horizontal and extremely stiff neck. That suggested an aquatic lifestyle, Mr Spiekman said, because such an incomprehensible neck would have made life on land uncomfortable. But paleontologists continued to argue as Tanystropheus actively pursuing under water like a perch ashore, with its long neck like a fishing rod.
To make matters more confusing, digs had found multiple skeletons of smaller Tanystropheus on Monte San Giorgio. If they belonged to youth, as some suggested, why did they have different teeth?
Mr Spiekman’s team first sought answers by scanning CT a copy of Tanystropheus’ head out of a museum in Zurich, and reconstruct it, which turned out to be difficult because “all the bones collapsed and because the skull of Tanystropheus is in many respects very different from other reptiles. ”
“I remember very well the day the model was ready and I was the first to see the face of this animal after 242 million years,” he said.
The reconstructed skull revealed several adjustments in the aquatic: nostrils placed on top of the snout, like a crocodile, and long, curved catches. Instead of actively pursuing prey, Mr. Spiekman said, she probably obstructed a troubled body of water, pulling its long neck forward to catch fish.
To test whether the bones of the smaller Tanystropheus belonged to youth or a separate species, the team studied thin sections of bones, prepared by the supervisor and co-author of Mr. Spiekman, Torsten Scheyer. A close look at the interior of the small bones revealed clear signs of a mature adult. That means two distinct species of Tanystropheus were which exist in the same waters: one large, one mini.
The two closely related animals seem to go to different storage types, the team reports, in an example of the phenomenon known as niche partitioning. The larger animal – newly named Tanystropheus hydroides – used its clenched teeth to hunt fish and squirrels; the teeth of the smaller species point to a diet of marine invertebrates such as shrimp.
With two solved mysteries, Mr. Spiekman and his team hope for a fresh look at the biomechanics of jaws, and that long, strange neck.
“People always thought Tanystropheus was an evolutionary dead end,” he said. “But the fact that Tanystropheus evolved into different species with very different lifestyles indicates that Tanystropheus and his neck were quite successful in evolutionary terms.”
