Paleontologists Discover Unusual New Species of Erasmosaurus: Traskasaura Sandrae

Traskasaura Sandrae, a 12 m long Erasmosaurus (a type of plesiosaurus) that inhabited the Cretaceous Sea 85 million years ago, showcases an unusual combination of primitive and advanced traits, setting it apart from other Erasmosaurus. This distinctive set of adaptations enabled the marine reptile to hunt its prey from above.

The first Traskasaura fossil was unearthed in 1988 within late Cretaceous strata in the Haslam Formation on Vancouver Island, Canada.

Since then, additional fossils have been excavated from the same layers, including isolated right humeri, as well as components of the chest, guard bones, limbs, and a preserved juvenile skeleton.

Initially described in 2002, the fossil gained recent prominence when it was adopted as the official crest fossil of British Columbia.

“Fossils of Prisiosaurus have been recognized in British Columbia for decades,” states Professor F. Robin O’Keefe from Marshall University.

“Nevertheless, despite its designation as a fossil in 2023, the identity of the organisms that produced it has remained enigmatic.”

“Our recent research published today will finally clarify this enigma.”

“I comprehend the scientific uncertainty surrounding this taxa.”

“It exhibits an odd mix of primitive and advanced features. Notably, the shoulders are unlike any other plesiosaur I’ve encountered, and I’ve seen quite a few.”

With the naming of Traskasaura Sandrae, the Pacific Northwest can finally claim a distinct Mesozoic reptile.”

“Thus, this area, known for its rich contemporary marine biodiversity, was once home to a variety of extraordinary marine reptiles from the dinosaur age.”

In the original description of the fossil in 2002, experts were hesitant to classify a new genus based solely on the discovered adult Erasmosaurus skeleton.

The skeletal remains presented a relatively limited number of discernible traits.

However, the newly discovered, well-preserved partial skeleton allowed the research team to illuminate much about the Erasmosaurus morphology found in the Pantledge River, ultimately categorizing it as a new genus and species.

Traskasaura Sandrae possessed a notably lengthy neck, with at least 36 well-preserved cervical vertebrae, comprising at least 50 bones in total.

“And there is no significant knowledge yet; Traskasaura Sandrae boasts an impressive array of autodynamic bones that exhibit its strong ability to swim downward,” remarked Professor O’Keefe.

“This peculiar blend of features is linked to its hunting techniques. It utilizes this capability for descending swimming to ambush its prey from above.”

“The prey included abundant ammonites known from the region.”

Survey results will be published in Journal of Systematic Palaeontology.

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F. Robin O’Keefe et al. 2025. Taxonomy of a remarkable new Erasmosaurus from the Santonian of Vancouver Island: British Columbia’s official province fossil name. Journal of Systematic Palaeontology 23 (1); doi:10.1080/14772019.2025.2489938