Claudia Steffensen was ready to take a beautiful hike in the Valtellina Orobie Mountains in 2024. She never expected to discover something paradigm-shifting. While trekking through the Ambria Valley, she noticed some strange fossil-like markings on a rock slab. Not sure what she was seeing, she took a few pictures and sent them to her nature photographer friend. In the process of doing so, she set in motion a sequence of events that would alter the history of the region forever.
When word of the discovery was passed on, Cristiano Dal Sasso, a paleontologist at Milan’s Museum of Natural History, became fascinated. He began to investigate what is called “Rock Zero” a 1,700 meter high site containing ancient traces of reptilian footprints. Dal Sasso soon realised that Steffensen’s discovery was the missing piece of the puzzle he had been searching for. Since 2023, hikers have been walking right past these prehistoric imprints without even knowing it, until scientists confirmed they were the fossilized tracks of at least five different species of reptiles, amphibians and even insects.
Finding a Forgotten Ecosystem
The discovery of Rock Zero has offered a rare opportunity to see into the Permian period, a time before the dinosaurs. Fossilized footprints, plants, as well as raindrop imprints accumulated in the hardened mud, revealing that this area was once a rich territory. Some tracks are from animals that were up to three meters in length and suggest that large reptiles once roamed the land here.
Fossils were found as high as 3,000 meters above sea level, quite a far distance from where these creatures would have actually lived; in lakes and on riverbeds. Geologists attribute the preservation of these imprints to the changes in terrain and climate patterns which buried the area for millions of years.
Then and Now
During the Permian period, volcanic activity and an increase in the planet’s temperature caused the environment to reshape itself completely, leading to one of the worst mass extinctions in the history of the planet. Recently, melting glaciers and rockslides are unravelling prehistoric traces that have been hidden under the ice, offering major scientific leaps forward and a stark reminder of the planet’s ever-changing terrain.
In the meantime, Rock Zero is a site that paleontologists from the University of Pavia and the Museum of Natural History of Milan are still investigating. It’s possible that future excavations will reveal even more fossils and thus expand knowledge about life before dinosaurs.
A Discovery for the Ages
What was initially a hike became one of the biggest paleontological discoveries of the last decade. Thanks to the sharp eyesight and quick action of Claudia Steffensen, Rock Zero became a vital piece of the Earth’s ancient map. Some of the fossils have been moved to the Museum of Natural History of Milan for preservation and there is already talk about the preservation of this site for future generations. It’s clear that an instant of curiosity can cascade into major scientific and historical breakthroughs. In addition to its scientific significance, Rock Zero is one of the few examples that represent what has happened on our planet, at a certain point in history, in such a detailed manner. It’s still possible that during the study of these ancient imprints, new species will be discovered, or some conclusions will be made about how early reptiles and amphibians lived, cohabitated, and survived in their environment. This discovery not only contributes to the knowledge of past ecosystems, but also highlights the necessity of the preservation of the geological artifacts for future generations.
