Nearly 250 million years ago, a very strange reptile patrolled the shores and bays of the Triassic Alps. Called Tanistropheus, it had a toothed head and a body echoed by that of modern monitor lizards. But between them stretched a horizontal, giraffe-like neck.
The question of how this 20-foot creature used that nine-foot neck has made paleontologists meaningless for more than 100 years and is considered “one of the most amazing animals that has ever lived,” said Stephen Spickman, a paleontologist at the University. in Zurich, Switzerland,, “How can this animal even breathe or swallow?”
But research published last week in Current Biology, including a new reconstruction of his skull, shows evidence that his body is prepared for a water hunting strategy and that the creature is in two varieties: regular and miniature.
Tanistrophey was originally described in 1850, based on several bone-like tubes. It wasn’t until the 1930s, when more complete fossils appeared in Monte San Giorgio, Switzerland, that scientists realized they were looking at the vertebrae in the neck of a strange reptile whose way of life they could not understand.
Decades passed until paleontologist Karl Chanz in 1988 showed that the ribs under the cervical vertebrae were blocked, forming a horizontal and extremely rigid neck. This suggests a watery lifestyle, Mr Speikman said, because such a stubborn neck would make life on land uncomfortable. But paleontologists continued to debate whether Tanistropheus actively chased underwater prey or landed on land, using its long neck as a fishing rod.
To make matters more confusing, the diggers had found numerous skeletons of a smaller Tanistrophey. of Monte San Giorgio. If they belong to minors, as some suggest, why did they have different teeth?
Mr. Spickman’s team first sought answers by CT scanning a sample of Tanistrophey. head from a museum in Zurich and reconstruct it, which proved difficult because “all the bones were wrong together and because Tanistrofey’s skull very different from other reptiles in many ways. “
“I remember very clearly the day the model was completed and I was the first to see the face of this animal in 242 million years,” he said.
The reconstructed skull revealed several aquatic adaptations: nostrils located at the top of the snout, like a crocodile, and long curved teeth. Instead of actively chasing the prey, Mr Speakman said, she probably ambushed them in murky water and moved forward with her long neck to snap fish.
To check whether the bones of the smaller Tanistrophey belonged to a young or individual species, the team examined thin sections of bone prepared by Mr. Spickman’s supervisor and co-author, Thorsten Scheyer. A closer look at the interior of the small bones revealed clear signs of a fully grown adult. This meant two different types of Tanistropheus were coexisting in the same waters: one big, one mini.
The two closely related animals appear to have gone after different species of prey, the team said, as an example of a phenomenon known as niche splitting. The larger animal, the newly named Tanystropheus hydroids, used its rods with teeth to catch fish and squid; the teeth of smaller species point to a diet of marine invertebrates such as shrimp.
With two mysteries solved, Mr. Speikman and his team hope to re-examine the biomechanics of the jaws and this long, strange neck.
“People have always thought Tanistropheus was an evolutionary dead end,” he said. “But the fact that Tanistropheus evolved into different species with very different lifestyles shows that Tanistropheus and his neck were quite successful in evolution.”