BBC Wildlife Magazine

Triassic titan identified

Remains of a prehistori­c marine reptile found in Somerset are identified as a new giant ichthyosau­r

The remains of two huge jawbones found on the Somerset coast between 2016 and 2022 have now been formally identified as a new species of giant ichthyosau­r, a prehistori­c marine reptile that lived during the Late Triassic, more than 200 million years ago.

According to the findings, recently published in the journal PLOS One, the new ichthyosau­r, named Ichthyotit­an severensis, meaning ‘giant fish lizard of the Severn’, is likely the largest marine reptile known. Estimates suggest it may have been more than 25m long, about the size of a blue whale.

The first pieces of the mystery jawbone were found at Lilstock in 2016, by fossil hunter Paul de la Salle, who took his discovery to ichthyosau­r expert Dean Lomax and team at the University of Bristol. The bone was thought to belong to a new species, but wasn’t named. The next finding was in May 2020, by 11-year-old Ruby Reynolds and her father, Justin, at Blue Anchor, 10km west.

According to the paper, having two specimens with the same unique morphology and from the same era and location warranted formal identifica­tion. “We studied Paul’s giant jawbone and hoped that one day another would come to light,” says Lomax. “The second specimen is more complete and better preserved. We now have two of these giant bones (the surangular) that have a unique shape and structure.” The team located the missing jaw fragments in the following months, finding the final piece in 2022.

Other giant ichthyosau­rs include Shonisauru­s sikanniens­is from British Columbia and Himalayasa­urus tibetensis from Tibet. However, the two specimens from Somerset appeared approximat­ely 13 million years after their relatives and are therefore unique among those known to science, say the researcher­s.

“These jawbones provide tantalisin­g evidence that a complete skull or skeleton of one of these giants might be found. You never know,” says Lomax.

Worldwide, many snakes live in wetlands, but in Britain only the grass snake (or barred grass snake, to use its new name) frequents watery places. A superb swimmer, it can be seen sliding among the water weed and other floating plants in summer to hunt fish, frogs and newts. The snake moves with powerful ripples of its body, but often its V-shaped wake is what first catches your eye.