Fossil of Long and Narrow-Snouted Ichthyosaur Uncovered in England

Paleontologist Dean Lomax of the University of Manchester and colleagues have identified a new genus and species of leptonectid ichthyosaur from a fossilized specimen found in Dorset, England.

Reconstruction of the life of Xiphodracon goldencapensis. Image credit: Bob Nicholls.

The almost complete skeleton of a dolphin-sized ichthyosaur was discovered near Golden Cap in 2001 by Dorset fossil collector Chris Moore.

The specimen includes a skull with a huge eye socket and a long, sword-shaped snout, and represents a new genus and species.

The fossil dates back to the Pliensbachian age of the Lower Jurassic, between 193 and 184 million years ago.

“I remember seeing the skeleton for the first time in 2016. At the time I knew it was unusual, but I didn’t expect it to play such a crucial role in helping to fill a gap in our understanding of the complex turnover of fauna during the Pliensbachian,” Dr Lomax said.

“This period is quite crucial for ichthyosaurs, as several families went extinct and new families emerged, but the new species is what one might call a ‘missing piece of the ichthyosaur puzzle’.”

“It is more closely related to species from the Upper Lower Jurassic, and its discovery helps determine when the faunal turnover occurred, being much earlier than previously thought.”

“This is the first described genus of Lower Jurassic ichthyosaur described in the region in over 100 years.”

The skeleton and skull of Xiphodracon goldencapensis. Image credit: Dean Lomax.

Appointed Xiphodracon goldencapensisthe new ichthyosaur was about 3 m (10 ft) long and would have fed on fish and squid; the remains even show what could be traces of his last meal.

“This skeleton provides essential information for understanding the evolution of ichthyosaurs, but also contributes to our understanding of what life must have been like in Britain’s Jurassic seas,” said Dr Erin Maxwell, an ichthyosaur expert at the State Museum of Natural History in Stuttgart.

“The limb bones and teeth are malformed in such a way that they indicate serious injury or illness while the animal was still alive, and the skull appears to have been bitten by a large predator – probably another, much larger species of ichthyosaur – which gives us a cause of death for this individual.”

“Life in the Mesozoic oceans was a dangerous prospect. »

The authors identified several characteristics in Xiphodracon goldencapensis which have never been observed in any ichthyosaur.

The strangest is a strange and unique bone around the nostril – called a lacrimal – which has tooth-like bony structures.

“Thousands of complete or nearly complete ichthyosaur skeletons are known from strata before and after the Pliensbachian,” said Professor Judy Massare, an ichthyosaur expert at the State University of New York at Brockport.

“The two faunas are very distinct, without any species in common, even if the overall ecology is similar. »

“Clearly, a major change in species diversity occurred at some point in the Pliensbachian.”

“Xiphodracon goldencapensis helps determine when the change occurred, but we still don’t know why.

The study was published this month in the journal Paleontology articles.

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Dean R. Lomax and others. 2025. A new ichthyosaur with a long, narrow snout sheds light on complex faunal turnover during an undersampled Early Jurassic (Pliensbachian) interval. Paleontology articles 11 (5): e70038; doi: 10.1002/spp2.70038