In a first for Canadian paleontology, a Cretaceous fossilized dragonfly wing, uncovered in Alberta's Dinosaur Provincial Park, has been identified as a new species. It's also the first known dragonfly fossil from Canada's dinosaur aged rocks. The find, led by McGill University researchers, sheds light on a 30-million-year gap in the evolutionary history of dragonflies.
The fossil was discovered in 2023 by a McGill undergraduate student during a vertebrate paleontology field course led by Prof. Hans Larsson.
"We were excavating an area where many leaf fossils had been found by cracking rocks," said André Mueller, lead author of the study and a Master's student in Larsson's lab in McGill's Department of Biology. "When the partial wing was uncovered, we were taken by surprise as we were not expecting to find any insects there."
The team named the new species Cordualadensa acorni. Because of its remarkable distinction and unique anatomy, they even created a new family - Cordualadensidae - to classify it. They chose "acorni" for the species name to honour of University of Alberta lecturer John Acorn, entomologist and science communicator at the University of Alberta who has promoted the natural history of Alberta for decades including with the TV show "Acorn, the Nature Nut."
"This is the first ever dinosaur-aged dragonfly found in Canada," said Mueller. "Its wingspan was about the width of a human hand, and while small, it would have been an important part of the Cretaceous ecosystem-a tasty raptor snack, no doubt."
The fossil was found in the 75-million-year-old Dinosaur Park Formation, a world-renowned site known for its rich diversity of dinosaur bones. But until now, the area's insect fossil record was virtually nonexistent. The only previous insect found in the formation was a microscopic aphid trapped in amber.
"This discovery not only doubles our knowledge of insects from the park, but also represents a completely unknown preservation method, impression fossils, for insects fossils in the area," said Alexandre Demers-Potvin, a former Larsson PhD student and now a postdoctoral fellow in McGill's Department of Biomedical Engineering. "We've now started finding more insect fossils by expanding where and how we search. The diversity of insect life during this time was likely much greater than we thought."
The new fossil helps fill a major 30 million year old evolutionary gap. It's the first known North American member of a large group of dragonflies called Cavilabiata. "The wing anatomy tells us this species was adapted for gliding; a trait associated with migratory dragonflies today and possibly a key to their success," said Larsson. "This specimen also provides insight into what life was like in Canada 75 million years ago, adding an important new missing piece of the ecological puzzle of one of the most diverse dinosaur-bearing sites in the world".
The study's findings were published in the Canadian Journal of Earth Sciences. The fossil and its artistic reconstruction, created by McGill undergraduate Alex Anderson, provides the first glimpse of what ancient Canadian dragonflies may have looked like.
About the study
New family of fossil dragonfly (Odonata, Cavilabiata) from the Late Cretaceous (Campanian) Dinosaur Park Formation, Alberta, Canada by André S. Mueller, Alexandre V. Demers-Potvin, and Hans C.E. Larsson was published in the Canadian Journal of Earth Sciences.
Funding for fieldwork was supported by an NSERC Discovery Grant (RGPIN/04370-2022) awarded to HCEL. This research was performed using the infrastructure of the Adaptable Earth Observation System, funded by the Quebec government, McGill University, and the Canadian Foundation of Innovation project 36146.
