‘Sword Dragon’ ichthyosaur had enormous eyes and a lethal snout

Introducing the “Sword Dragon,” a newly identified species of ichthyosaur—a group of predatory marine reptiles that thrived in the oceans during the age of dinosaurs.

The remarkably preserved fossilized skeleton was discovered along the Jurassic Coast of the UK, near Golden Cap, in 2001, and remained in the collections of the Royal Ontario Museum in Canada for years.

“They recognized it as something significant,” explains Dean Lomax from the University of Manchester, UK. “Plans were made to research it, but they never materialized.”

Lomax and his research team have now successfully prepared and identified the specimen, characterized by its large eye socket and elongated, sword-like snout. The fossil features “needle-like piercing teeth, perfectly adapted for consuming soft-bodied prey such as squid and fish,” according to Lomax. “One can almost envision how this creature lived, likely relying on keen eyesight to hunt, potentially in low-light conditions.”

This creature measured around 3 meters in length—comparable to that of a typical bottlenose dolphin—and roamed the oceans during the Early Jurassic period, specifically the Pliensbachian epoch, approximately 193 to 184 million years ago.

Notably, it exhibits features previously unknown in any ichthyosaurs, including a distinct lacrimal bone structure surrounding the nostrils that has prong-like projections. “The exceptional preservation level of the three-dimensional cranial sutures and delicate features like the lacrimal and prefrontal projections is remarkable,” states Aubrey Roberts from the Natural History Museum at the University of Oslo, Norway.

A dark mass found between the ribs might indicate its last meal, although the researchers could not determine its specifics.

The researchers have designated the ichthyosaur as Xiphodracon goldencapensis, translating to the Sword Dragon from Golden Cap due to its fearsome-looking snout.

This specimen sheds light on the evolution of ichthyosaurs. “The primary significance of this discovery is its age,” states Roberts. Prior to the end-Triassic extinction event, enormous ichthyosaurs, such as Ichthyotitan, were formidable super-predators reaching sizes near 25 meters, comparable to blue whales. These giants vanish from the fossil record following the end-Triassic extinction event around 201.4 million years ago, marking the onset of the Jurassic Period.

Numerous smaller ichthyosaur remains have been unearthed from the Jurassic, according to Lomax. Many of these fossils demonstrate significant diversity, with no overlap between two distinct types found before and after the Pliensbachian period.

“Triassic ichthyosaurs were remarkably diverse and unusual,” notes Neil Kelley from Vanderbilt University, Tennessee. “In contrast, their Jurassic successors have often been perceived as more uniform, exhibiting a dolphin-like morphology.”

Xiphodracon introduces additional complexity to our understanding of ichthyosaurs, illustrating that Jurassic ichthyosaurs likely pursued various lifestyles with differing dietary needs, swimming capabilities, and habitat preferences.