If you found it 47 million years after your death, what do you see when scientists examine the contents of your stomach? The process of preserving one last meal of pizza pockets cannot survive as firmly as the contents of the stomach discovered inside the fly that enjoyed his last meal at Eosin.
Published in the journal Current Biology, a new study was able to peek into the stomach of a fly spread over pollen about 47 million years ago, providing insights into the feeding behavior of flies and its environmental role as pollinators. Using photogrammetry, a team of scientists was able to detect a large amount of pollen inside the stomach of a fly trapped inside an ancient fossil found in the UNESCO World Heritage Site “Messel Pit”. The species – which is new to science – sits within the genus Hirmoneura and has a body length of eleven millimeters (less than half an inch).
Despite its advanced age, the fly survived the process of preserving its stomach contents and revealed that it would rest with a full stomach full of pollen when it popped its claws. This is the first evidence that these flies have pollinated in the past. Bees and butterflies often top environmental leaderboard as pollinators, but the role of other insects, including flies (and ants!), is often overlooked. This new study found that dipterans (larger fly families) have been doing their job of distributing pollen for about 50 million years (already autonomous bubble-blowing drones could be future pollinators).
Palynology is the study of particulates, focusing on pollen grains. The method developed in the field enables scientists to get an idea of the existing climate as well as which plant-related species came from when the pollen formed.
The team working on the Messel Peat Fly was able to identify that its last food came from the plants Sapotaceae (Sapotaceae) and Oleaceae (olives) and the more modern genus Decodon (water willow) and Parthenocissus (Virginia creeper) family plants. Said Dr Sonja Wedmann of the Senckenberg Research Institute and Natural History Museum in Frankfurt in a statement, “Food residues such fossils are extremely rare worldwide. They allow for the animals’ way of life and feeding, as well as for the environment in which the animals were subject.”
“Flying to save energy was undoubtedly avoiding long-haul planes between their food plants. We therefore assume that the trees involved in pollen can found in relatively small areas.” The pollen ratio supports the team’s hypothesis that flies were feeding on trees growing at the edge of Messel Lake and its surrounding forests. Therefore, the fossil shows, Wedmann said, that Eocene still played a role in the distribution of pollen by flies.
“We assume that flying pollen played an important role in transport and thus in the propagation of several plant families. It is possible that flies were more important than bees for pollinating tropical trees – and still are.”
