Paleontologists in Canada say they have recovered a dinosaur tail vertebra from 75- to 80-million-year-old marine rocks on a small island off the coast of British Columbia, providing the clearest evidence yet that bird-like ornithomimosaurs once roamed the ancient Pacific coastline of North America.
Life restoration of Quipalong henanesnsis, an ornithomimosaurian dinosaur that lived in what is now China during the Maastrichtian age of the Late Cretaceous, between 72 and 67 million years ago. Image credit: PaleoNeolitic / Sci.News.
Ornithomimosaurs were a group of fast-running, bird-like theropod dinosaurs that lived during the Cretaceous period.
They had long legs, long necks, slender bodies, toothless beaks and relatively small heads, giving them a strong resemblance to modern ostriches.
Some species, such as Gallimimus and Ornithomimus, could grow more than 4 m (13 feet) long.
Despite being theropods, ornithomimosaurs are thought to have been omnivores or opportunistic feeders, eating plants, small animals and possibly eggs.
They were likely among the fastest dinosaurs of their time, with some estimates placing their top speed at around 50-60 km/h (31-37 mph).
In their new paper, Dr. David Evans, a paleontologist at the University of Toronto and the Royal Ontario Museum, and his colleagues described a fossilized vertebra from the tail of an ornithomimosaur.
The fossil dates back to the Campanian age of the Late Cretaceous, between 80 and 75 million years ago.
The specimen was collected in August 1999 from marine sediments of the Cedar District Formation on Denman Island, part of the Nanaimo Group of western Canada.
“The fossil is, to date, only the second reported occurrence of dinosaur skeletal material from the Nanaimo Group, and the first from Canadian outcrops,” the paleontologists wrote in the paper.
They suggest the ornithomimosaur bone may have washed out to sea from the western margin of ancient North America, possibly carried by currents, shoreline transport, or even scavengers.
Another possibility is that it came from a floating carcass that drifted offshore before disarticulating.
“Based on current interpretations of the paleolatitude of the Nanaimo Basin, the specimen was probably roughly latitudinally equivalent to outcrops of the Two Medicine and Judith River formations to the east, part of the northern faunal province of Campanian Laramidian dinosaurs along the Western Interior Seaway,” the researchers wrote.
“To date, remains of ornithomimosaurs identifiable to lower taxonomic levels have not been described from the Judith River and Two Medicine formations, although a rich ornithomimid fauna is known from the Dinosaur Park Formation of Alberta with species in several genera known from complete skeletons.”
“Whether or not Pacific coastal dinosaurs may also have had a latitudinal diversity gradient, and whether or not the intervening mountain ranges impacted dinosaur biogeography by promoting allopatric diversification in the Campanian, are questions that can only be answered with additional fossil discoveries.”
The team’s paper was published on April 17 in the journal FACETS.
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Victoria M. Arbour et al. 2026. An ornithomimosaur from the Campanian Cedar District Formation (Nanaimo Group) of Denman Island, British Columbia, Canada. FACETS 11; doi: 10.1139/facets-2023-0079
