An unusual ancient marine reptile has been formally recognized, decades after its fossil was initially found in Canada.

This 12-meter creature, Traskasaura Sandrae, was a type of predator contemporaneous with dinosaurs. It resembled a long-necked plesiosaurus with peculiar anatomy and a distinct top-down hunting approach.

“The presence of its bizarre characteristics — it was an animal that appeared quite unusual — made it nearly impossible for researchers to classify it,” said Professor F. Robin O’Keefe, a paleontologist at Marshall University and the lead author of the study, as reported by BBC Science Focus.

The original fossil was found along the Pantledge River on Vancouver Island in 1988, having remained on the ground for 85 million years. Surprisingly, it was nearly complete, with the skull, neck, limbs, and tail, although one side had deteriorated. “It appeared well-preserved from a distance,” O’Keefe noted.

It wasn’t until certain elements were uncovered that the pieces began to align.

“The remarkable preservation allowed us to investigate some of the odd features of the adult fossils and to interpret what we were observing,” O’Keefe explained. “The discovery of this second skeleton permitted its classification as a new species.”

Among its unique traits is its shoulder structure, which diverges from that of known plesiosaurs, facing downward.

In contrast, its flipper resembles an inverted airplane wing, featuring a more curved underside rather than the top. “This emphasized the animal’s upside during its unique hunting approach,” O’Keefe noted.

This is significant as it implies that Traskasaura hunted in an atypical manner: by descending upon its prey from above.

“Normally, reptiles swim in water where light comes from above, leading animals to hunt upwards as they spot prey silhouetted against the surface light,” O’Keefe explained. “This animal approached it differently.”

Its potential prey likely included creatures related to modern squids and octopuses, as well as extinct coiled-shelled ammonites, which were crushed with its sharp teeth.

Despite its formidable size and appearance, Traskasaura was by no means the apex of the ancient seas. “It was substantial, yet it didn’t possess a notably large neck or head,” O’Keefe remarked. “If a Mosasaur, known for its large teeth, were to seize it, it could inflict serious damage.”

Nevertheless, Traskasaura would have thrived in the ocean, feasting on abundant resources. Unfortunately, like all plesiosaurs, the species faced extinction during the mass extinction event approximately 66 million years ago.

“They were flourishing, and their ecosystems were relatively robust until an asteroid impact decimated all the large animals,” O’Keefe stated.

Read more:

About our experts

F. Robin O’Keefe received his Honorary Biology degree from Stanford University in 1992 and a Ph.D. in 2000, specializing in evolutionary biology at the University of Chicago. He has been a professor at Marshall University since 2006, teaching over 200,000 undergraduate students across various subjects, from human anatomy to comparative zoology and Earth’s history.

A recognized expert in marine reptiles from the age of dinosaurs, O’Keefe was awarded the 2013 Drinko Distinguished Research Fellowship for his work on the reproduction of plesiosaurs.