Scientists have identified a new dinosaur species featuring a prominent sail-like structure along its back that may have been used for attracting mates, with fossils discovered on England’s Isle of Wight.
The iguanodontian dinosaur has been named Istiorachis macaruthurae, with “Istiorachis” meaning “sail spine” and the species name honoring Dame Ellen MacArthur, the famous sailor from the Isle of Wight who set a world record for the fastest solo non-stop voyage around the world in 2005.
PhD student Jeremy Lockwood from the University of Portsmouth and Natural History Museum identified the new species after analyzing 125-million-year-old fossils that had previously been assumed to belong to existing known species from the island.
“While the skeleton wasn’t as complete as some others that have been found, no-one had really taken a close look at these bones before,” Lockwood explained. “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.”
The retired GP’s research, published in Papers in Palaeontology, suggests the dinosaur’s pronounced sail-like back structure likely served as visual signaling for sexual display purposes.
“Evolution sometimes seems to favor the extravagant over the practical,” Lockwood noted. “In modern reptiles, sail structures often show up more prominently in males, suggesting these attributes evolved to impress mates or intimidate rivals. We think Istiorachis may have been doing much the same.”
The research team compared fossilized bones with databases of similar dinosaur backbones to understand how these sail-like formations evolved, finding that Istiorachis’s spines were “more exaggerated than is usual in Iguanodon-like dinosaurs.”
Professor Susannah Maidment of the Natural History Museum praised Lockwood’s work, noting he has “single-handedly quadrupled the known diversity of smaller iguanodontians on the Isle of Wight” over the past five years, demonstrating there is still much to learn about Early Cretaceous ecosystems in the UK.