A few years ago, Mallorcan researcher Josep Juárez made a surprising find during a paleontological survey in the area—a complete insect larva that had left a slight imprint of organic remains on the two sides that were left exposed when the rock split in half. The detailed study of the fossil had to wait, but eventual examination with a powerful microscope revealed that it was a unique discovery.

The larva, very well preserved, belongs to a group of insects that we all know, the dipterans—that is, true flies, mosquitoes, midges, and gnats. Although thousands of fossil dipterans have been found across the globe, both in thinly layered rocks and in amber, this specimen, 247 million years old (early Middle Triassic)—older than the earliest dinosaurs—is the oldest dipteran ever found. This record was previously held by fossils found in France, about one or two million years younger than those from Estellencs.

Enrique Peñalver, from the Spanish National Research Council (CSIC) at the Spanish Geological Survey (CN-IGME), and first author of the recent study on the new fossil published in Papers in Palaeontology, says, "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."

Rafel Matamales-Andreu, paleontologist from the Balearic Museum of Natural Sciences (FJBS-MBCN) and another author of the study, has devoted several years to unravel the environment of this region during the Triassic period, and the changes it underwent for millions of years. "If we were able to visit the region at the beginning of the Triassic, we would see large rivers and floodplains under a climate similar to that found in tropical Africa today, alternating dry and rainy seasons," he points out.