According to scientists who published their findings in the PLOS journal on Monday, the bone, called a surangular, was likely part of the reptile's lower jaw.
The researchers predicted the reptile's length by comparing this surangular bone to the same bone in the largest ichthyosaur skeleton ever found, a 69-foot Shonisaurus sikanniensis discovered in British Columbia. The fossil found on the English shore could be the largest known fossil of an ichthyosaur ever discovered.
— Dean R. Lomax (@Dean_R_Lomax) April 9, 2018
"As the specimen is represented only by a large piece of jaw, it is difficult to provide a size estimate, but by using a simple scaling factor and comparing the same bone in S. sikanniensis, the Lilstock specimen is about 25 percent larger," Lomax explained.
"This bone belonged to a giant" University of Manchester paleontologist Dean Lomax said, Reuters reported.
"The largest reported ichthyosaurs lived during the Late Triassic (~235-200 million years ago), and isolated, fragmentary bones could be easily mistaken for those of dinosaurs because of their size," the study's abstract states.
In 1850, a large fossil from the Late Triassic period was found by scientists near Aust Cliff in Gloucestershire, UK. It was initially believed to belong to a giant dinosaur, although it was never positively identified. The discovery of the Somerset fossil suggests that the Aust bone could be another ichthyosaur surangular, Lomax wrote in a Monday press release.
"One of the Aust bones might also be an ichthyosaur surangular. If it is, by comparison with the Lilstock specimen, it might represent a much larger animal. To verify these findings, we need a complete giant Triassic ichthyosaur from the UK — a lot easier said than done!" Lomax wrote.