A skeleton found on Britain’s Jurassic Coast has been identified as a new species of ichthyosaur, a type of prehistoric marine reptile that once ruled the seas, scientists said on Friday.

Comparable in size to a dolphin, the ichthyosaur has been named Xiphodracon goldencapensis, or the “Sword Dragon of Dorset”, after the English county where the near-complete skeleton was discovered.

It is “the only known example of its kind in existence and helps to fill an important gap in the evolutionary fossil record of ichthyosaurs”, the University of Manchester said.

Ichthyosaur expert Dean Lomax, an honorary research fellow at the university, led the three-strong team of paleontologists who carried out the analysis.

Ichthyosaurs were reptiles who spent their lives under water. They are not considered to have been dinosaurs.

The sword dragon dates back to the Pliensbachian period, which occurred around 190 million years ago.

The skeleton was discovered near Golden Cap, in Dorset, in 2001, but has only recently been analysed by palaeontologists.

It includes a skull with a huge eye socket and a long sword-like snout.

Scientists said the animal would have been about three metres long and would have eaten fish and squid.

The research was published on Friday in the Papers in Palaeontology journal.

The skeleton is due to go on display at the Royal Ontario Museum in Toronto, Canada.