New sail-backed dinosaur unearthed from Isle of wight fossils
A new dinosaur species, *Istiorachis macarthurae*, with a dramatic sail-like spine has been identified from Isle of Wight fossils. Discovered by Jeremy Lockwood, it likely evolved its striking features for sexual selection, broadening understanding of Early Cretaceous iguanodontians
London: A new dinosaur with a dramatic sail along its back and tail has been identified from fossils found on the Isle of Wight, off the south coast of England, the University of Portsmouth revealed on Friday.
Scientists believe the species may have evolved its eye-catching look to impress potential mates, possibly suggesting it evolved by sexual selection.
The new iguanodontian dinosaur was identified by Jeremy Lockwood, a retired general practitioner (GP), as part of his PhD studies at the University and the Natural History Museum of London.
His findings are described in a new paper published on Friday in the scientific journal ‘Papers in Palaeontology’.
He discovered by carefully re-examining dinosaur bones held in the collections at the Dinosaur Isle Museum on the Isle of Wight.
“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,” said Lockwood. “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. Evolution sometimes seems to favour the extravagant over the practical,” he added further.
“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 is usually because of sexual selection,” he added.
Until Lockwood’s work, the 125-million-year-old fossil material had been assumed to belong to one of the two known iguanodontian dinosaur species from the Isle of Wight.
On closer inspection, Lockwood realised the animal would have probably possessed a pronounced sail-like structure along its back, helping to set it apart from other dinosaurs found on the island.
Lockwood has named the new dinosaur Istiorachis Macarthurae after a famous Isle of Wight resident. The name Istiorachis means ‘sail spine’, while Macaruthurae honours Dame Ellen MacArthur – the English sailor who in 2005 set a world record for the fastest solo non-stop voyage around the world on her first attempt and who comes from the Isle of Wight.
“Jeremy’s careful study of fossils that have been in museum collections for several years has brought to life the iguanodontian 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,” said Susannah Maidment, who was part of the team studying the fossils from the Natural History Museum.
“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,” she said.
Scientists point out that Istiorachis appears to highlight a broader evolutionary trend. Research shows that elongation of neural spines in iguanodontians began in the Late Jurassic, before becoming a relatively common feature during the Early Cretaceous geological period millions of years ago.
However, true hyper-elongation, where spines stretch to more than four times the height of the vertebral body, remains rare.
