Moths and butterflies fluttered around Earth in the Jurassic Period, millions of years earlier than previously thought, even before there were flowers to provide them with nectar for food.
A new study by a group of researchers including Boston College Research Professor Paul K. Strother offers new support for that theory.
Strother and his colleagues made the scientific case, in an article published Wednesday in Science Advances, for the moths and butterflies known as Lepidoptera emerging during the Jurassic period.
Previously, it had been thought they emerged during the Cretaceous Period, when the first flowers emerged, Boston College said in a statement.
Visiting a colleague in Germany in 2012, Strother was looking at core samples drilled from the German countryside for pollen, spores, pieces of plants, and insect legs that had been trapped in sediment millions of years ago, the college said.
The sample dated to the boundary between the end of the Triassic Period and the beginning of the Jurassic Period, approximately 200 million years ago, researchers said. The Cretaceous Period began 145 million years ago.
Strother, who works at the college’s Weston Observatory, noticed features similar to those found in Lepidoptera wings.
“The consensus has been that insects followed flowers,” Strother said in the statement. “But that would be 50 million years later than what the wings were saying. It was odd to say the least, that there would be butterflies before there were flowers.”
“I thought, ‘OK, this is weird,’” Strother said in a telephone interview.
Strother was part of a team that also included researchers from Utrecht University in the Netherlands and natural history museums in Germany.
Strother said the discovery was exciting, but he couldn’t really prove it. That was up to Timo van Eldijk, a Utrecht University undergraduate at the time, working with Torsten Wappler of the German natural history museum Hessisches Landesmuseum Darmstadt.
So how did the primitive moths and butterflies get food, if there were no flowers?
The researchers say that they developed a sucking proboscis to get nutrition by drawing off water drops from the tips of immature gymnosperm seeds. (Gymnosperms, which include conifers and other plants, have exposed seeds.)
“It turns out that there are amino acids and sugars that are dissolved in the pollen droplet ... so they can get food from them,” Strother said in the interview.
The insects later transferred their feeding preference onto angiosperms [flowering plants with their seeds protected in fruits], he said.
He said the insects and plants ended up co-evolving, with the insects getting food from the flowers and the flowers using them to transfer pollen.
The theory that ancient butterflies fed on gymnosperms is not new, he said. “But they didn’t actually have the fossils to back up those ideas. Now they do.”