Monstrous marine reptile ichthyosaur was the biggest ever marine animal

In a study published in the journal PLOS ONE, scientists have revealed discovery of a jawbone fossil that is said to be of ichthyosaur that scientists estimated at up to 85 feet (26 meters) long—approaching the size of a blue whale.

The fossil was found on a rocky English beach. Scientists say that ichthyosaur, which appears to be the largest marine reptile ever discovered, lived 205 million years ago at the end of the Triassic Period, dominating the oceans just as dinosaurs were becoming the undisputed masters on land. The bone, called a surangular, was part of its lower jaw.

The marine reptile’s length was estimated by comparing the fossil to the same bone in the largest ichthyosaur skeleton ever found, a species called Shonisaurus sikanniensis from British Columbia that was 69 feet (21 meters) long. The newly discovered bone was 25 percent larger.

Fossil collector Paul de la Salle, affiliated with the Etches Collection in Dorset, England, found the bone in 2016 at Lilstock on England’s Somerset coast along the Bristol Channel.

Ichthyosaurs swam the world’s oceans from 250 million years ago to 90 million years ago, preying on squid and fish. The biggest were larger than other huge marine reptiles of the dinosaur age like pliosaurs and mosasaurs. Only today’s filter-feeding baleen whales are larger. The blue whale, up to about 98 feet (30 meters) long, is the biggest animal alive today and the biggest marine animal ever.

The researchers estimated the new ichthyosaur at 66 to 85 feet long (20 to 26 meters).

It appears to have belonged to an ichthyosaur group called shastasaurids. Because the remains are so incomplete, it is unclear whether it represents a new ichthyosaur genus or is a member of a previously identified genus, said paleontologist Judy Massare of the State University of New York College at Brockport.