Hydroids tanystrofeni, the last described species of reptile that lived 242 million years ago (Triassic period), was about 6 m (20 feet) long, with the neck making up half that length – three times longer than the bay of her.
One of the most prominent Triassic reptiles, Tanystropheus is characterized by an extremely long and rigid neck that is almost three times the length of its chest, despite being composed of only 13 elongated hyper vertebrae.
It was first described as a single species, Tanystropheus longobardicus, in 1852, and has been a perplexed paleontologist ever since.
For a long time, scientists were not sure if this reptile lived on land or in water. Her weird body did not make things clear one way or another.
“Tanystropheus looked like a brave crocodile with a very long neck, “said Dr. Olivier Rieppel, a paleontologist at the Field Museum.
In the same region where many of the greats Tanystropheus fossils were found, in what is now Switzerland, there were also fossils from eye-like reptiles that were only about 1.2 m (4 meters) long.
So not only were the scientists unsure if these were land dwellers or marine animals, but they also did not know if the smallest specimens were juveniles or even a particular species.
To solve these two long mysteries, Dr. Rieppel and colleagues used the latest technology to see details of animal bones.
Big Tanystropheus The fossil skulls were crushed, but the researchers were able to take CT scans of the fossil plates and generate 3D images of the bone fragments inside.
The skulls had key features, including the nose on top of the shell like a crocodile, which suggested Tanystropheus lived in water.
Maybe he stood waiting, waiting for the fish and squid animals to swim, and then grabbed them with their long, curved teeth. She may have come to earth to lay eggs, but overall, she remained in the ocean.
“That neck makes no sense in a terrestrial environment. “It’s just a difficult structure to accomplish,” said Dr. Rieppel.
To find out if the small specimens were juveniles or a particular species, the scientists examined the bones for signs of growth and aging.
“We looked at crossed sections of bone of the small type and were very excited to find many growth rings. This tells us that these animals were mature,” said Dr. Torsten Scheyer, a paleontologist at the University of Zurich.
The authors named the largest species Hydroids tanystrofeni. The small form bears the original name Tanystropheus longobardicus.
“Small species that can feed on small shell animals, such as shrimp, in contrast to large species that eat fish and squid,” said Dr. Stephan Spiekman, a paleontologist at the University of Zurich.
“We were waiting for the strange neck of Tanystropheus specialize in a single task, like the neck of a giraffe. But actually, it allowed some lifestyles. “
“For many years now we have had our suspicions that there were two types of Tanystropheus, but until we were able to scan the larger specimens we had no definitive evidence. Now we do, “said Dr. Nick Fraser, holder of natural sciences at the National Museums of Scotland.
“It is extremely important to discover that there were two completely separate species of this long-tailed reptile that swam and lived together in the coastal waters of the great Tethys Sea approximately 240 million years ago.”
The team newspaper was published in the magazine Current biology.
Stephan NF Spiekman et al. Water habits and warm separation in the extremely long reptile of the Triassic neck Tanystropheus. Current biology, published online 6 August 2020; doi: 10.1016 / j.kub.2020.07.025