Scientists have discovered butterfly fossils that are approximately 200 million years old, pushing back the date for the origins of Lepidoptera — a group that includes butterflies and moths — by millions of years and suggesting the insects evolved their long straw-like tongues before nectar-bearing flowers existed.
The study is published in the journal Science Advances.
“These scales are the oldest evidence of moths and butterflies,” said lead author Timo van Eldjik, who was an undergraduate at Utrecht University in the Netherlands during the study, as reported by The New York Times. “It extends the range to which we know butterflies existed by about 10 million years.”
Van Eldjik discovered the fossils when drilling deep in northern Germany to search for ancient pollen, particularly during the mass extinction at the end of the Triassic Period. After dissolving the rock in chemicals that remove any inorganic material, the team discovered some unknown scales. Van Eldjik used a single nostril hair as a dissection probe.
“The nose hair has just the right length and springiness for getting a pollen grain, or in this case the butterfly scale, to adhere to it,” van Eldjik said. “I was just provided these by my professor, I don’t know whose hair it was. It’s probably best not to ask.”
Among the approximately 70 butterfly scales or scale fragments, the researchers found that about 20 were hollow — interesting because virtually all butterflies today with hollow scales have a long, nectar-sucking proboscis. But because flowers are thought to have appeared on Earth only about 130 million years ago, this presents a conundrum.
“That creates this problem,” said van Eldjik. “If they had a proboscis, what were they using it for?”