Giant, 82-foot lizard fish discovered on UK beach could be largest marine reptile ever found

Scientists have unearthed the remains of a gigantic, 200 million-year-old sea monster that may be the largest marine reptile ever discovered.

The newfound creature is a member of a group called ichthyosaurs, which were among the dominant sea predators during the Mesozoic Era (251.9 million to 66 million years ago). The newly described species lived during the end of the Triassic Period (251.9 million to 201.4 million years ago).

Ichthyosaurs had already attained massive sizes by the early portion of the Mesozoic, but it was not until the late Triassic that the largest species emerged.

While the Mesozoic is known as the age of the dinosaurs, ichthyosaurs were not themselves dinosaurs. Instead, they evolved from another group of reptiles. Their evolutionary path closely mirrors that of whales, which evolved from terrestrial maMMAls that later returned to the sea. And like whales, they breathed air and gave birth to live young.

The newly discovered ichthyosaur species was unearthed in pieces between 2020 and 2022 at Blue Anchor, Somerset in the United Kingdom. The first chunk of the fossil was noticed atop a rock on the beach, indicating that a passerby had found it and set it there for others to examine, the researchers explained in the paper. The researchers published their findings April 17 in the journal PLOS One.

The reptile's remains are made up of a series of 12 fragments from a surangular bone, which is found in the upper portion of the lower jaw. The researchers estimate the bone was 6.5 feet (2 meters) long and that the living animal was about 82 feet (25 m) long.

The researchers named the sea monster Ichthyotitan severnensis, meaning giant lizard fish of the Severn, after the Severn Estuary where it was found. The team believes it is not only a new species but an entirely new genus of ichthyosaur. More than 100 species are already known.