Steve Etches unearthed the well-preserved ichthyosaur fossil in limestone on the Jurassic Coast in Dorset. He thought the fossil was so unusual that he gave it to experts at the University of Portsmouth, southern England, to study.

Megan Jacobs, a researcher at the University of Portsmouth and a PhD student at Baylor University, Texas, who has spent years working on ichthyosaurs, identified it as a new genus and species.

The two-meter long ichthyosaurus, which lived 150 million years ago, has been named the “Etches sea dragon” (Thalassodraco etchesi).

Scientists have now identified five species of ichthyosaur from the Late Jurassic period in the UK. They are known as sea dragons because of their usually large teeth and eyes.

Fossils of ichthyosaurs from this period are rare, according to Jacobs, but this one was well-preserved because it settled in a very soft seafloor when it died. This meant the front part of its body sunk into the mud, protecting it from scavengers that ate the tail end.

The newly discovered species has even larger eyes than other ichthyosaurs, covering almost a quarter of its whole skull, which would have allowed it to see in low light conditions deep underwater, said Jacobs, who explained that its tiny smooth teeth were probably used to catch soft prey such as squid.

This is the smallest ichthyosaur found so far. The largest known ichthyosaur lived in North America during the Triassic period and had skulls measuring almost five meters in length — 10 times larger than the Thalassodraco etchesi.

The fossil will be displayed at the Etches Collection, a museum in Dorset which also houses Etches’ many other discoveries.