Protoanisolarva juarezi, the gnat larva representing the oldest known diptera, 247 million years old, found in Mallorca, Spain. Credit: CN-IGME CSIC
Key points:
- Discovery of a fossil dating from “just” a few million years after the greatest mass extinction provides the earliest evidence of the insect group that includes mosquitoes and flies.
- Excellent preservation of the fossil has allowed detailed studies, including determining its breathing system.
- The fossil also provides clues as to the postapocalyptic environment at the beginning of the Triassic.
Scientists have made a discovery that shows how insects adapted to a postapocalyptic world.
A few years ago, which searching near the Balearic Islands in Spain, researcher Josep Juarez found a complete insect larva that had left a slight imprint of organic remains on two sides of exposed rock that split in half. Subsequent examination revealed the larva belonged to dipterans—an order that includes flies, mosquitoes, midges and gnats.
Researchers then realized the fossil was rare. At 247 million years old—older than most dinosaur fossils—not only is it the oldest dipteran ever found, but it is also incredibly well-preserved.
“While I was inspecting it under the microscope, I put a drop of alcohol on it to increase the contrast of the structures, and I was able to witness in awe how the fossil had preserved both the external and internal structures of the head, some parts of the digestive system, and, most importantly, the external openings to its respiratory system, or spiracles,” said first author Enrique Peñalver from the Spanish National Research Council.
Findings published in Papers in Paleontology show the fossil belongs to a dipteran larva, now known as Protoanisolarva juarez, which had a breathing system similar to those still found in various insect groups existing today.
The larva fed on organic matter from the soil millions of years after the most dramatic mass extinction in the history of life on Earth, which erased more than 80 percent of the species and led to the end of the Palaeozoic Era.
“We have been able to look at some of the adaptations by the first dipterans to the postapocalyptic environment at the beginning of the Triassic, for instance, a breathing system that is still found in different groups of insects today,” said study author Ricardo Pérez-de la Fuente from Oxford University.
The scientists have now described a new genus and species related to modern window- or wood-gnats—and named it Protoanisolarva juarezi, or “Juárez’s ancestral anisopodoid larva,” honoring its discoverer.