Rare Ostrich-Like Ornithomimosaur Tail Bone Discovered on Denman Island, Canada

Paleontologists have identified a single tail vertebra from an indeterminate ornithomimosaur—the first definitive dinosaur skeletal fossil from Canadian outcrops of the Nanaimo Group—on Denman Island, British Columbia. Collected in August 1999 from marine sediments of the Cedar District Formation, the Campanian-aged bone (~75–80 million years old) provides the clearest evidence yet that swift, bird-like “ostrich dinosaurs” once inhabited the ancient Pacific coastline of North America.

The isolated caudal vertebra (RBCM.EH2010.001.0001) was recovered from shallow-marine rocks that normally preserve fish, ammonites, and marine reptiles. Its discovery is remarkable because dinosaur remains are exceptionally rare in these deposits; the Nanaimo Group had previously yielded only one other dinosaur bone, from Washington state. CT scans and comparative anatomy confirm its ornithomimosaur affinities, showing the characteristic hollow centrum and neural arch morphology seen in relatives such as Ornithomimus and Struthiomimus from the Judith River and Two Medicine formations.

Published in May 2026 in the journal FACETS by Victoria M. Arbour and colleagues, the study highlights how this single element expands our understanding of Late Cretaceous terrestrial ecosystems along western North America’s margin. The animal was likely a fast-running, omnivorous theropod that foraged near coastal plains before its remains were washed into the sea.

This find underscores the value of persistent collecting in underrepresented regions and suggests ornithomimosaurs were more widespread across the continent than previously recognized. As more material surfaces from the Nanaimo Group, Denman Island’s modest tail bone may prove to be the first chapter in a richer story of British Columbia’s Cretaceous dinosaurs.