In a remarkable find announced May 28, 2026, paleontologists have recovered the first confirmed tyrannosaurid tail vertebra from fully marine deposits in Canada—pushing the boundaries of how these iconic predators interacted with the Western Interior Seaway.

The 8-centimeter caudal vertebra, belonging to a mid-sized tyrannosaur roughly 6–7 meters long, was excavated from the marine shales of the Bearpaw Formation near Lethbridge, Alberta. Precise biostratigraphy and radiometric dating place the specimen at approximately 75 million years old (Campanian stage). Unlike typical terrestrial tyrannosaur sites in Dinosaur Provincial Park, this bone was entombed in fine-grained offshore muds alongside ammonites, mosasaur teeth, and fish scales—clear evidence the carcᴀss drifted out to sea before burial.

CT scans reveal classic tyrannosaurid features: deeply pneumatic neural arches, robust chevron facets, and a distinctive “hourglᴀss” centrum shape. Lead researcher Dr. Emily Bamforth (Royal Tyrrell Museum) states: “This is the first direct proof that a tyrannosaur entered the seaway, either by swimming or as a floating carcᴀss. It rewrites ᴀssumptions about their coastal ecology.” The vertebra shows no bite marks, suggesting natural death rather than predation or scavenging.

The discovery strengthens evidence that large theropods occasionally ventured into shallow marine environments, perhaps while hunting along shorelines or during floods. It also highlights the Bearpaw Formation’s potential as a “marine graveyard” for terrestrial dinosaurs. As more material is prepared, this lone tail bone may unlock new insights into tyrannosaur distribution, taphonomy, and the dynamic interface between land and sea 75 million years ago. A small fragment, yet a giant leap in our understanding of Cretaceous Canada.