In what is considered a world first, scientists have discovered a 47 million-year-old fossilized fly with a stomach full of pollen. This find proves that ancient flies fed on the microspores of several different species of subtropical plants.
"The rich pollen content we discovered in the fly’s stomach suggests that flies were already feeding and transporting pollen 47 million years ago and shows it played an important role in the pollen dispersal of several plant taxa", said in a statement Fridgeir Grímsson from the Department of Botany and Biodiversity Research of the University of Vienna.
"Flies were major pollinators in ancient (sub-)tropical equivalent ecosystems and might even have outshined the bees."
The fossil was discovered in a disused quarry near Frankfurt, Germany. The scientists have identified the fossilized fly as a novel species of ancient, short-proboscid fly also known as Hirmoneura messelense.
The contents of the belly of this fly were remarkably well preserved and showed traces of pollen from several plant families.
"The fly fed on pollen from at least four plant families—Lythraceae, Vitaceae, Sapotaceae, and Oleaceae—and presumably pollinated flowers of two extant genera, Decodon and Parthenocissus. We interpret the feeding and foraging behavior of the fly, reconstruct its preferred habitat, and conclude about its pollination role and importance in paratropical environments," wrote the researchers in their study.
"This represents the first evidence that short-proboscid nemestrinid flies fed, and possibly feed to this day, on pollen, demonstrating how fossils can provide vital information on the behavior of insects and their ecological relationships with plants."
The scientists also speculated that the fly fed on plants that grew close to each other at the forest margin surrounding the ancient Messel lake. "It is likely that the fly avoided long-distance flights between food sources and sought pollen from closely associated plants", concluded Grímsson.
The study was published in the journal Current Biology.