A new species of large plant-eating dinosaur that roamed the Isle of Wight around 125 million years ago has been identified.
The specimen, which weighed as much as an African elephant, represents the most complete dinosaur discovered in the UK in a century with 149 bones in total, researchers said.
Comptonatus chasei, named after the late fossil hunter Nick Chase and the place where it was found, the cliffs of Compton Bay, belongs to a group of herbivorous dinosaurs known as iguanodontians, bulky creatures often described as the “cows of the Cretaceous”. [145-66 m years ago]” by paleontologists.
Jeremy Lockwood, a PhD student at the University of Portsmouth, said: “This animal would have been around a tonne (1,000kg), about the size of a large American bison man.
“Evidence from fossil footprints found nearby shows it was probably a herding animal, so it’s possible that large herds of these heavy dinosaurs may have thundered around when scared off by predators on the floodplains more than 120m years ago.”
For the study, published in the Journal of Systematic Paleontologythe researchers analyzed every part of the fossil, including skull, teeth, spine and leg bones as well as a pubic femur “about the size of a dinner plate”.
Lockwood said it was unclear why the hip bone, found at the bottom of the abdomen, was so large, but added: “It [the bone] was probably for muscle attachments, which might mean that its mode of locomotion was a little different, or it might have been to support the stomach contents more effectively, or even have been involved in how the animal breathed, but all these theories are somewhat speculative.”
When Comptonatus was discovered, the specimen was thought to be a different type of dinosaur called Mantellisaurus, three-toed herbivores that lived in Britain more than 120 million years ago.
But Lockwood said that Comptonatus differs from Mantellisaurus because of the “unique features in its skull, teeth and other parts of its body”.
He said: “Its lower jaw has a straight lower edge, whereas most iguanodontians have a jaw that curves downward.”
Dr Susannah Maidment, a senior researcher and paleontologist at the Natural History Museum, said Comptonatus showed rapid rates of evolution in iguandontic dinosaurs during that period.
The work could help researchers understand how ecosystems recovered after an extinction event at the end of the Jurassic period (200-149m years ago), she added.
Comptonatus was discovered in 2013 by Chase, who died of cancer just before the Covid-19 pandemic. It took Lockwood and his colleagues several years before the sample could be prepared for analysis.
Lockwood, a retired GP, said Chase had a phenomenal nose for finding dinosaur bones, but that this was the first dinosaur to be named after him despite many “wonderful discoveries”, including the most complete Iguanodon skull yet ever found in Britain.
Eight extinct species from the Isle of Wight have been named over the past five years, which Lockwood said showed that the Isle of Wight and nearby areas may once have had one of the world’s most diverse ecosystems.
