The oldest known butterflies existed before flowers
Butterflies and moths have a long, tongue-like mouthpiece. It is known as a proboscis. It helps them slurp up tasty nectar from floral tubes. There is a common (and very logical) theory about this handy appendage. The theory states that butterflies and moths evolved their proboscises in response to plants that developed flowers. But that theory might be wrong. That's according to Ben Guarino of the Washington Post. A new study has uncovered evidence suggesting that butterflies and moths had proboscises millions of years before flowers came into existence.
An international team of researchers discovered the fossilized remains of tiny scales. These scales coat the bodies of butterflies and moths. Researchers made this discovery while studying fossil cores. They dated to the late Triassic and early Jurassic periods.
Timo van Eldijk can push 70 scales beneath a microscope. He used a needle tipped with a human nostril hair. He is graduate student at Utrecht University. It is in the Netherlands.
“The nose hair has just the right length and springiness for getting a pollen grain to adhere to it. But in this case, the goal is a the butterfly scale.” That's what van Eldijk told Nicholas St. Fleur of the New York Times. “I was just provided these by my professor. I don’t know whose nose hair it was. It’s probably best not to ask.”
Van Eldijk then set about analyzing the structure of the scales. Some were solid and compact. This is not particularly unusual. Previous research has shown that this structure was typical of early moths and butterflies. They used mandibles to chomp their food. But van Eldijk was surprised to discover something else. The scales were hollow. This is a feature only seen among moths and butterflies with proboscises.
“If you find the hollow scales,” van Eldijk told Rebecca Hersher of NPR, “you know the innovation of the proboscis must have occurred before that.”
This discovery was described recently in the journal Science Advances. It threw researchers for a loop. That's because the scales are about 200 million years old. This makes them the oldest known Lepidoptera remains by about 10 millions years. Previous molecular studies on the creatures suggest a similar early evolution of proboscis-bearing butterflies and moths. That's according to Fabien Condamine. He is a butterfly researcher who was not involved in the study.
The fossils are also about 70 million years older than the first flowers, raising questions about the evolution and function of the proboscis. It is possible that there is simply a gap in the fossil record, and flowers existed earlier than scientists thought. But the study authors believe the more likely explanation is that butterflies and moths evolved their proboscises before flowers came into being. This possibly helped them lap up the sugary pollination drops produced by gymnosperms. These are the most common group of plants that sprung from the ground during the Jurassic.