Hiker accidentally discovers 280 million-year-old lake ecosystem in Italian Alps

While walking in Valtellina Orobie Park in the Italian Alps, a hiker accidentally discovered traces of an ancient lake ecosystem dating back 280 million years, located at a latitude that was likely tropical at the time. These include numerous reptile footprints and slithers, testifying to the richness of the ecosystem before the Great Permian-Triassic Extinction. This discovery could provide valuable information on the major upheavals to come due to current global warming.

Since the 1850s, anthropogenic global warming has led to the loss of 30 to 40% of the surface area of ​​Alpine glaciers and almost half of their volume. Although dramatic from an ecosystem point of view, this has paradoxically brought to light numerous prehistoric traces and fossils.

Claudia Steffensen was hiking in the Valtellina Orobie mountain park in Lombardy when she came across some of these tracks. “ I put my foot on a rock, which seemed strange to me because it looked more like a slab of cement. I then noticed these strange circular designs with wavy lines. I looked closer and realized they were footprints “, she told the Guardian.

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The hiker then contacted experts from the Natural History Museum of Milan, the University of Pavia and the Natural History Museum of Berlin, who confirmed that these were indeed exceptionally fossilized footprints. well preserved. The number and diversity of traces suggest that this was an ancient, extremely rich ecosystem. The findings were presented last week at a press conference at the Natural History Museum in Milan, after the slabs were recovered through airborne operations.

Hundreds of footprints from at least 5 different species

The footprints discovered by Steffensen are located at an altitude of 1,700 meters and are believed to belong to a large reptile 2-3 meters long, about the same size as Komodo dragons (Varanus komodoensis) current. The tracks indicated very slender fingers, trails left by the swipe of long, flexible tails, and imprints of scaly skin.

Sediment analysis suggests they lived in the area around the end of the Permian (the last period of the Paleozoic before the dinosaurs) around 280 million years ago. “ At that time, dinosaurs did not yet exist, but the authors of the largest footprints found must have had considerable dimensions: up to 2-3 meters in length », Says in a press release Cristiano Dal Sasso, paleontologist at the Natural History Museum of Milan and the first expert to be contacted about the discovery.

Previous excavations have made it possible to map hundreds of other fossilized traces up to 3,000 meters above sea level, notably on the vertical walls of Pizzo del Diavolo di Tenda, Pizzo dell’Omo and Pizzo Rondenino, as well as in rubble accumulated by landslides below. Stratified rocks, even those a few meters wide, showed imprints of tetrapods (reptiles and amphibians) and invertebrates (insects and arthropods) whose alignment suggests they formed trackways. These traces belong to at least 5 different species of animals.

Clues on the impacts of global warming on ecosystems

The slabs analyzed by the researchers indicate marks from waves hitting the shores of what are apparently ancient lakes. Traces of raindrops were also noted. The remarkable state of preservation of these traces and imprints would come from the fact that they were made when the layers of sandstone and shale were still water-soaked sand and mud. The water recedes periodically and leaves the layers of sediment exposed to the sun, which hardens them. Rather than erasing the traces, the return of the water covers them with a new protective clay layer.

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« The shape and size of the traces indicate a quality of conservation and notable paleo-biodiversity, probably even greater than those observed in other deposits of the same geological age in the Orobic and Brescia sectors. “, says Lorenzo Marchetti of the Natural History Museum in Berlin. In addition to animal prints, fossilized fragments of stems and seeds have also been unearthed.

These discoveries could provide valuable information on the impacts of global warming on ecosystems. The Permian is in fact characterized by a rapid rise in temperatures comparable to that of today and culminated with the Great Extinction, a pivotal period in Earth’s history which eliminated around 90% of species. Intense volcanic activity has caused an increase in greenhouse gases, which in turn has caused melting ice caps and the development of increasingly arid tropical environments, leading to the extinction of many animals. . “ The past has a lot to teach us about what we risk leading the world towards today », Say the researchers.

However, more research is needed to confirm whether these findings can truly support climate modeling. “ There is still much to be done, as the research is in its early stages and many logistical issues will also need to be resolved. », says Doriano Codega, president of Orobie Valtellinesi Park. The latter granted a preliminary allocation of funds to continue the research.