A tiny fossil insect found near the city of Kamloops, British Columbia, points to a possible land connection between Canada and Australia.
Image credits Archibald, S. B., & Makarkin, V. N., (2020), The Canadian Entomologist.
Current relatives of this species live exclusively in Australia, the team explains, suggesting the possibility of a former connection between the two landmasses. The fossil, which the team describes as an insect from the “split-footed lacewing” family, is estimated to be 50 million years old.
Old ties
“These fossils are rare,” says Vladimir Makarkin of the Russian Academy of Sciences in Vladivostok, corresponding author of the study describing the fossil. “This is only the fourth one found from this time-span world-wide, and it’s the most completely preserved. It adds important information to our knowledge of how they became modern.”
The discovery is the latest in a series of fossil finds that are pointing to a Canada-Australia connection, the team explains. Furthermore, it raises some interesting questions regarding the global movement of animals and how it is impacted by shifts in climate and the position of continents over time
The split-footed lacewing family is very poorly documented, although we do know that it survived for at least 66 million years after the dinosaurs went extinct. The fossil’s identity — a new genus and species, Epinesydrion falklandensis — was determined as belonging to the split-footed family from the hallmark network of veins covering its wings.
Previous fossil insects of comparable age found in British Columbia and Washington have ties to families that currently inhabit Pacific-coastal Russia to the west and Europe, as these northern continents all used to be connected.
“Fifty million years ago, sea levels were lower, exposing more land between North America and Asia, and the Atlantic Ocean had not widened, leaving Europe and North America still joined across high latitudes,” says lead author Bruce Archibald.
However, we don’t know of any ancient land route between British Columbia and Australia. Compared to its position today, the land down under was closer to Antarctica and farther from Asia, meaning that any migrating animals needed to travel over vast stretches of ocean to reach Canada’s west coast.
Archibald says that “a pattern is emerging that we don’t quite understand yet, but has interesting implications”. They hypothesize that the issue might be tied to climate. The forests of the ancient British Columbian temperate upland (when this lacewing lived) had mild winters, probably without frost days. The climate of modern Australia shares these mild winters even in temperate regions.
“It could be that these insect groups are today restricted to regions of the world where climates in key ways resemble those 50 million years ago in the far western Canadian mountains,” says Archibald.
The team explains that understanding this species’ life and how it ended up on both of these modern continents can help us better piece together the history of our climate and continents.
The paper “A new genus and species of split-footed lacewings (Neuroptera) from the early Eocene of western Canada and revision of the subfamily affinities of Mesozoic Nymphidae” has been published in the journal The Canadian Entomologist.