For more than 150 years, scientists have mistakenly classified a group of fossil insects as damselfish, the familiar cousins of dragonflies that hover around wetlands eating mosquitoes. Although surprisingly similar, these fossils have oddly shaped heads, which researchers have always attributed to the distortion resulting from the fossilization process.
Now, however, a team of researchers led by Simon Fraser University (SFU) paleontologist Bruce Archibald has discovered that they were not damsels at all, but represented a new group of major insects closely related to them.
The results, published today in Zootaxons, show that the distinctive shape of the insect’s rounded, non-protruding eyes, placed near the head, are the defining characteristics of a suborder related to damselflies and dragonflies that the researchers named Cephalozygoptera.
“When we first started finding these fossils in British Columbia and Washington state, we initially thought they were damsels,” says Archibald.
But on closer inspection, the team noticed that they looked like a fossil that German paleontologist Hermann Hagen wrote about in 1858. Hagen set a precedent by linking the fossil to the suborder Damsels despite its shape. with a different head, which did not correspond at all to the young ladies.
Damsels have short, broad heads with conspicuously protruding eyes on either side. Hagen’s fossil, however, had a strangely rounded head and eyes. But he speculated that this difference was wrong, caused by distortion during fossilization.
“Paleontologists since Hagen had written that they were damsels with deformed heads,” Archibald says. “A few hesitated, but still assigned them to the Ladies’ Suborder.”
The SFU-led team, comprising Robert Cannings of the Royal British Columbia Museum, Robert Erickson and Seth Bybee of Brigham Young University and Rolf Mathewes of SFU, sifted through 162 years of scientific papers and found that numerous specimens Similar ones have been found since the time of Hagen.
They had a eureka moment when they realized that the strange heads of their new fossils were, in fact, their true form.
The researchers used the head shape that defines the fossil to name the new suborder Cephalozygoptera, which means “damsel’s head.”
The oldest known species of cephalozygoptera lived among dinosaurs during the Cretaceous Period in China, and their last existence dates back around 10 million years in France and Spain.
“They were important parts of the wetland food webs of ancient British Columbia and Washington around 50 million years ago, after the dinosaurs went extinct,” says Archibald. “Why they declined and died out remains a mystery.”
The team named 16 new species of cephalozygoptera. Some of the fossils were found on the traditional lands of the Colville Indian tribe in northern Washington state. Archibald and his co-authors therefore collaborated with the elders of the tribe to name a new family. They named the family “Whetwhetaksidae”, from the word “whetwhetaks”, which means dragonfly-like insects in the language of the Colville people.
Archibald has spent 30 years combing the fossil-rich deposits of southern British Columbia and the northern interior of Washington state. To date, together with others, he has discovered and named over 80 new species in the area.
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