Scientists have uncovered a new species of dinosaur which boasted a striking “eye-catching sail” running along its back and tail that may have been used to attract potential mates.
The newly identified iguanodontian dinosaur, whose remains were unearthed on the Isle of Wight, was discovered by PhD student Jeremy Lockwood from the University of Portsmouth and the Natural History Museum.
The retired GP has chosen to name the species in honour of sailor Dame Ellen MacArthur, who hails from the island off England’s south coast and gained fame for achieving a world record for the fastest solo non-stop circumnavigation of the globe in 2005.
The dinosaur has been christened Istiorachis macaruthurae, with the first term translating to “sail spine” and the second paying tribute to Dame Ellen’s family name.
Prior to Dr Lockwood’s examination, the fossils, which are 125 million years old, were believed to have belonged to one of two recognised iguanodontian dinosaur species from the Isle of Wight.
He said: “While the skeleton wasn’t as complete as some of the others that have been found, no-one had really taken a close look at these bones before”.
“It was thought to be just another specimen of one of the existing species, but this one had particularly long neural spines, which was very unusual.”
Dr Lockwood revealed, in his research published in the scientific journal Papers in Palaeontology, that the creature would have likely possessed a distinctive sail-like feature along its spine. He said: “Evolution sometimes seems to favour the extravagant over the practical.
“While the exact purpose of such features has long been debated – with theories ranging from body heat regulation to fat storage – researchers believe that the most likely explanation in this case is visual signalling, possibly as part of a sexual display and this usually is because of sexual selection.
“In modern reptiles, sail structures often show up more prominently in males, suggesting that these attributes evolved to impress mates or intimidate rivals. We think Istiorachis may have been doing much the same.”
During the research, scientists analysed the fossilised remains against a collection of comparable dinosaur vertebrae, enabling them to observe how these sail-like structures had developed over time.
Dr Lockwood explained: “We showed that Istiorachis’s spines weren’t just tall – they were more exaggerated than is usual in Iguanodon-like dinosaurs, which is exactly the kind of trait you’d expect to evolve through sexual selection.”
Professor Susannah Maidment, from the Natural History Museum, commented: “Jeremy’s careful study of fossils that have been in museum collections for several years has brought to life the iguandontian dinosaurs of the Isle of Wight.
“His work highlights the importance of collections like those at Dinosaur Isle, where fossil specimens are preserved in perpetuity and can be studied and revised in the light of new data and new ideas about evolution.
“Over the past five years, Jeremy has single-handedly quadrupled the known diversity of the smaller iguanodontians on the Isle of Wight, and Istiorachis demonstrates we still have much to learn about Early Cretaceous ecosystems in the UK.”