Tanystropheus hydroides, the newly-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 of that length — three times as long as its torso.

One of the most remarkable Triassic reptiles, Tanystropheus is characterized by an extraordinarily long and stiffened neck that is almost three times the length of its torso, despite being composed of only 13 hyper-elongated vertebrae.

For a long time, scientists weren’t sure whether this reptile lived on land or in the water.

To learn whether the small specimens were juveniles or a separate species, the scientists examined the bones for signs of growth and aging.

The authors named the larger species Tanystropheus hydroides.

The small form bears the original name Tanystropheus longobardicus.

“The small species likely fed on small shelled animals, like shrimp, in contrast to the large species which ate fish and squid,” said Dr.

“It is hugely significant to discover that there were two quite separate species of this bizarrely long-necked reptile who swam and lived alongside each other in the coastal waters of the great sea of Tethys approximately 240 million years ago.”.