According to foreign media reports, ancient predatory insects have been found in areas that were once considered uninhabitable. Fossil discoveries often help answer long-standing questions about how our modern world came to be. Sometimes, however, they only deepen the mystery, like the four neo-ancient insects recently discovered in British Columbia and Washington State.
The fossil species recently discovered by paleontologist Bruce Archibald from Simon Fraser University and Vladimir Makarkin of the Russian Academy of Sciences belongs to an insect known as snakefly, which has now been shown to have lived in the area about 50 million years ago. The study, published in Zootaxa, raises more about the evolutionary history of this slender insect and why they live in this place today.
The snake fly is a slender, carnivorous insect native to the Northern Hemisphere and clearly absent in the tropics. Scientists have traditionally believed that because they require cold winters to develop into adults, they can almost only grow in areas with winter frosts or colder weather. However, the climate experienced at fossil sites where these ancient species were found does not correspond to this explanation.
"The average annual climate here is mild, like Vancouver or Seattle today, but it's important that winters are very mild, with little or no frost," Archibald said, "and we can see this by the frost-intolerant plants that live in these forests, like palm trees, and more northerly plants like spruce." ”
Fossil sites where these ancient species were discovered spanned 1,000 kilometers of ancient highlands, stretching from Driftwood Canyon in northwestern B.C. to McCabe fossil sites in southern B.C., all the way to Republic City north of Washington.
According to Archibald, paleontologists have found species in these fossil sites of two families of snakeflies, both of which were previously thought to require cold winters to survive. However, now that the reality of discovery, each family seems to have adapted independently to the cold winter.
"Now we know that early in the evolutionary history of snakeflies, they lived in very warm climates in winter, so the question becomes, why can't they maintain the ability to live in these areas?" Why are snakeflies not found in the tropics today? Archibald said.
Previous fossil insects found at these sites suggest that they are linked to Europe, Russia's Pacific coast, and even Australia.
Archibald stressed that understanding how life adapted to climate through in-depth study of the past could help explain why species are distributed around the globe today, and may also help predict how further changes in the climate will affect this pattern.