A280-million-year-old fossil site has been uncovered in the Orobie Valtellinesi Park in the Italian Alps after melting snow revealed rock surfaces packed with ancient traces. The discovery includes footprints, plant remains, and even marks left by rain on soft sediment. Scientists say it offers an unusually complete snapshot of a long-lost ecosystem.
The find began in 2023 when a hiker noticedstrange patterns on a mountain trail. What started as a simple observation quickly turned into a major scientific investigation once the images reached researchers at the Natural History Museum of Milan.
What makes this site stand out is the level of detail preserved in the rock. Instead of isolated fossils, scientists are seeing a full environmental record, showing how animals, plants, and water once interacted in a Paleozoic landscape.
A Hiker’s Discovery That Changed Everything
The first clues came when Claudia Steffensen was hiking down a mountain path on a hot summer day. She told the Guardian she noticed a rock that looked unusual, “like a slab of cement,” before realizing it contained circular shapes and wavy lines that turned out to be footprints.
She took photos and sent them to a friend, photographer Elio Della Ferrera, who forwarded them to the Natural History Museum of Milan. According to museum researchers, that was enough to trigger fieldwork in the area, which soon revealed hundreds of fossil traces across cliffs and loose rock.
The site is now known to stretch across vertical walls and landslide deposits, with some traces found atnearly 10,000 feet above sea level. As mentioned by the Natural History Museum of Milan, this spread suggests that multiple ancient surfaces have been exposed over time, not just one single layer.
A Prehistoric World Preserved In Detail
The site contains traces from amphibians and reptiles, tail trails, plant fragments, seeds, and even marks that look like fossilized raindrops. Ripple patterns on the rock also point to ancient shallow water or lake edges.
Lorenzo Marchetti, sedimentology specialist at the Leibniz Institute for Research on Evolution and Biodiversity in Berlin, said the rock is so fine-grained that it preserved very small details.
“The very fine grain of the sediments, now petrified, has allowed the preservation of sometimes impressive details, such as the imprints of the fingertips and the belly skin of some animals.”
Instead of just bones or single fossils, the site preserves movement and behavior. Scientists can see how animals walked, where water flowed, and how sediments captured these moments.
Footprints That Lasted Millions of Years
The preservation process started when the area was covered in wet sandstones and clays. Ausonio Ronchi from the University of Pavia explained that animals left footprints while the ground was still soft and waterlogged.
As stated by Ronchi, the sun later dried and hardened the surface, and new layers of sediment covered it before the marks could be destroyed. This layering protected the impressions like a natural seal. Over time, they turned into stone, locking in details that would normally disappear quickly.
The site stayed hidden for millions of years until recent melting of snow and glaciers exposed the rock again. Scientists say this kind of exposure is now happening more often in high mountain areas as ice retreats.
Mountain Site Becomes a Field Lab
Today, the Orobie Valtellinesi Park is being studied like an outdoor laboratory. Park director Massimo Meratisaid teams are using drones to map steep rock walls and helicopters to recover fragile boulders that cannot be safely moved by hand. One of the first recovered stones containing reptile footprints.
“Dinosaurs did not yet exist at that time, but the authors of the largest footprints found here must have been still considerable in size,” said paleontologist Cristiano Dal Sasso from the Natural History Museum of Milan.
The footprints likely belong to at least five different species. He also noted that dinosaurs were not present at this time, although some of the animals were still relatively large.
The regional heritage authority, represented byStefano Rossi, said the site could become an important training ground for students and researchers. The idea is to study the fossils directly in the field, where the traces are still emerging from the rock.
