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A hiker in the northern Italian Alps has stumbled across the first trace of what scientists believe to be an entire prehistoric ecosystem, including the well-preserved footprints of reptiles and amphibians, brought to light by the melting of snow and ice induced by the climate crisis.
The discovery in the Valtellina Orobie mountain range in Lombardy dates back 280 million years to the Permian period, the age immediately prior to dinosaurs, scientists say.
Claudia Steffensen, from Lovero, a village in Sondrio province, and her husband were navigating their way along a rocky trail in the Ambria valley, close to the Swiss border, when she stepped on a light grey rock covered in “strange designs”.
“It was a very hot day last summer and we wanted to escape the heat, so we went to the mountains,” Steffensen told the Guardian. “On our way back down, we had to walk very carefully along the path. My husband was in front of me, looking straight ahead, while I was looking towards my feet. I put my foot on a rock, which struck me as odd as it seemed more like a slab of cement. I then noticed these strange circular designs with wavy lines. I took a closer look and realised they were footprints.”
Steffensen took a photo and sent it to her friend Elio Della Ferrera, a photographer who specialises in the natural world. Della Ferrera then sent the photo to Cristiano Dal Sasso, a paleontologist at the museum of natural history in Milan, who in turn consulted other experts.
The footprints, found 1,700 metres above sea level, turned out to belong to a prehistoric reptile.
The experts mapped out an area of the Valtellina Orobie nature park, including at altitudes of almost 3,000 metres, and visits to the site since summer 2023 have revealed hundreds of other fossilised footprints of reptiles, amphibians and insects, which they said were often still aligned to form “tracks”. The traces are believed to have come from at least five different species of animal.
In a statement Dal Sasso said: “Dinosaurs did not yet exist, but the authors of the largest footprints must still have been of a considerable size – up to 2-3 metres long.”
Lorenzo Marchetti, an ichnologist, or trace fossils specialist, at the museum of natural history in Berlin, said the preservation of the footprints was such that they revealed “impressive details”. “For example, the imprints of fingernails and the belly skin of some animals,” he added.
The ecosystem also revealed fossilised fragments of plants, seeds and even imprints of raindrops.
The Permian period ended with the largest mass extinction, provoked by a sudden rise in temperature, that the world has ever known. Global warming today has revealed traces of other prehistoric animals in the Italian Alps, including the footprints of a crocodile-like reptile found at an altitude of 2,200-metres in Altopiano della Gardetta, in the province of Cuneo in Piedmont.
“The discovery in the Ambria valley is also an effect of climate change,” said Doriano Codega, president of the Valtellina Orobie nature park. “The exceptional thing was the altitude – these relics were found at very high levels and were very well preserved. This is an area subjected to landslides, so there were also rock detachments that brought to light these fossils. This is a very important paleontological discovery.”
Some of the relics were recently brought to Milan and displayed at the natural history museum this week. Research will continue at the site, experts said.
Steffensen, whose discovery has become known as “Rock Zero”, said: “I’m feeling very proud, especially to have made a small contribution to science.”