The remains of a large herbivorous animal discovered on the Isle of Wight in 2013 have been described by scientists as the "most complete" dinosaur skeleton found in the UK in the last 100 years.
The specimen, which comprises 149 bones, including a pubic hip bone the size of a "dinner plate", was found in the cliffs of Compton Bay on the Isle of Wight by fossil collector Nick Chase.
Sadly, Nick died of cancer just before the COVID-19 pandemic. The newly described species – Comptonatus chasei – is named after him.
Since its discovery more than 10 years ago, scientists – including University of Portsmouth PhD student Jeremy Lockwood, who helped with the dinosaur's excavation – have been busy analysing the bones.
"This animal would have been around a ton, about as big as a large male American bison," explains Jeremy. "And evidence from fossil footprints found nearby shows it was likely to be a herding animal, so possibly large herds of these heavy dinosaurs may have been thundering around if spooked by predators on the floodplains over 120 million years ago."
The study determined that the skeleton represented a new genus and species.
"I've been able to show this dinosaur is different because of certain unique features in its skull, teeth and other parts of its body. For example its lower jaw has a straight bottom edge, whereas most iguanodontians have a jaw that curves downwards. It also has a very large pubic hip bone, which is much bigger than other similar dinosaurs. It's like a dinner plate!"
Jeremy can only speculate as to why the pubic hip bone needed to be so big. "It was probably for muscle attachments, which might mean its mode of locomotion was a bit different, or it could have been to support the stomach contents more effectively, or even have been involved in how the animal breathed, but all of these theories are somewhat speculative."
Jeremy named the dinosaur Comptonatus chasei. Comptonatus is a combination of the location the specimen was found in (Compton Bay) and the Latin word 'tonatus', meaning 'thunderous'; while chasei pays homage to Nick Chase who discovered the bones in 2013.
"Nick had a phenomenal nose for finding dinosaur bones -- he really was a modern-day Mary Anning," says Jeremey. "He collected fossils daily in all weathers and donated them to museums. I was hoping we'd spend our dotage collecting together as we were of similar ages, but sadly that wasn't to be the case.
"Despite his many wonderful discoveries over the years, including the most complete Iguanodon skull ever found in Britain, this is the first dinosaur to be named after him."
Dr Susannah Maidment, a palaeontologist at the Natural History Museum and senior author of the paper said "Comptonatus is a fantastic dinosaur specimen: one of the most complete to be found in the UK in a century.
"Its recognition as a new species is due to incredibly detailed work by NHM Scientific Associate Dr Jeremy Lockwood, whose research continues to reveal that the diversity of dinosaurs in southern England in the Early Cretaceous was much greater than previously realised.
"The specimen, which is younger than Brighstoneus but older than Mantellisaurus (two iguandontian dinosaurs closely related to Comptonatus) demonstrate fast rates of evolution in iguandontian dinosaurs during this time period, and could help us understand how ecosystems recovered after a putative extinction event at the end of the Jurassic Period."
Eight new species of dinosaur have been described on the Isle of Wight in the last five years, revealing that Wessex was one of the world's most diverse ecosystems in the Early Cretaceous.
The dinosaur has been added to the collections at the Dinosaur Isle Museum in Sandown on the Isle of Wight.
The paper was published in the Journal of Systematic Palaeontology.
Main image credit: John Sibbeck
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