A rare and exceptionally well-preserved fossil of a dolphin-sized prehistoric reptile has been identified as a previously unknown species, now named the “sword dragon.” This remarkable discovery sheds new light on marine reptile evolution during the Early Jurassic period.
The fossil, unearthed near Golden Cap on Dorset’s Jurassic Coast in 2001 by fossil enthusiast Chris Moore, belongs to an ichthyosaur species dubbed Xiphodracon goldencapensis. Its name reflects the creature’s distinctive long, sword-like snout—‘xipho’ meaning sword and ‘dracon’ meaning dragon in Greek and Latin. Measuring approximately three meters in length, the sword dragon likely preyed on fish and squid as it swam through the ancient seas of the Pliensbachian stage, around 184 to 193 million years ago.
Despite thousands of ichthyosaur fossils found in Dorset, this is the first discovery of an Early Jurassic ichthyosaur in the region in over a century. The fossil had remained largely unstudied until recently, after being acquired by the Royal Ontario Museum in Canada.
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Dr. Dean Lomax, an ichthyosaur expert and research fellow at the Universities of Manchester and Bristol, led the team that analyzed the specimen. He described the find as a crucial missing piece in understanding a significant faunal turnover—a period of extinction and emergence of new families—among ichthyosaurs during the Pliensbachian. “Xiphodracon is more closely related to species from the slightly later Early Jurassic, helping us pinpoint when this evolutionary shift occurred—earlier than previously thought,” Dr. Lomax explained.
Co-author Professor Judy Massare from the State University of New York emphasized the significance of this species in dating the ecological shifts among ichthyosaurs. “The fossil record before and after the Pliensbachian shows distinctly different faunas with no overlap in species, indicating major changes in biodiversity,” she said. “Xiphodracon helps clarify the timing of these shifts, though the causes remain a mystery.”
Dr. Erin Maxwell, ichthyosaur researcher at the State Museum of Natural History Stuttgart and co-author, highlighted the fossil’s insights into Jurassic marine life. The sword dragon’s limb bones and teeth exhibit signs of injury or disease, and its skull bears bite marks from a larger predator, likely another giant ichthyosaur. “This gives us a rare glimpse into the dangers these creatures faced in prehistoric oceans,” Dr. Maxwell noted.
The discovery of Xiphodracon goldencapensis not only enriches the ichthyosaur fossil record but also deepens our understanding of early marine ecosystems during a pivotal time in Earth’s history.