A fossil dragonfly wing found impressed in a rock, has given scientists a rare glimpse into Canada’s Cretaceous insects. Discovered in Alberta’s Dinosaur Provincial Park, the 75-million-year-old insect has been named Cordualadensa acorni. It is the first Mesozoic dragonfly ever found in Canada.
“The taxon represents the only Mesozoic dragonfly for Canada. This discovery provides a missing link in the evolutionary transition from the early Cretaceous [dragonfly] to extant families”, wrote the researchers in their paper.
Cordualadensa acorni. (Photo Courtesy: McGill University)
Just the wing impression can tell us lots
The fossilized wing, measuring about the width of a human hand, is unusual for its preservation. It is preserved as an impression fossil, a rare form for insect remains in Dinosaur Provincial Park. Insects are usually found trapped in amber or encased in sediment, This new method of exceptional preservation could hint at the presence of more undiscovered insects in local rock layers.
The anatomical features of the fossilized wing indicate the dragonfly was built for smooth, efficient gliding, similar to modern migratory dragonflies. This suggests Cordualadensa was not a sluggish, clumsy flier but a graceful navigator. Even if “this guy would have inevitably been a tasty raptor snack“, according to Andre Muller
“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“
Filling in a Dragonfly Timeline
Up until this find, the fossil record of dragonflies in North America was silent for a long period, especially in the late Cretaceous. By introducing Cordualadensa acorni, scientists have filled a 30-million-year gap in the evolutionary history of these flying insects.
Further, this is the first North American representative of the “Cavilabiata”, a large group of dragonflies, pushing back their known geographical spread significantly. It tells us these insects were flying over ancient Canada much earlier than we knew.
Beyond the science, this discovery offers a richer view of what life was like in late Cretaceous Alberta. Dinosaur Provincial Park is already one of the most diverse and intensely fossiliferous formations on Earth. It now gets a new entrant to its impressive roster.