A wildlife photographer who was exploring a remote pocket of the Italian Alps has discovered thousands of dinosaur footprints preserved in the vertical face of a mountainside.
In September, Elio Della Ferrera was looking for deer and vultures in Stelvio National Park, near the Swiss-Italian border, when he noticed a rock face riddled with unusual depressions through his binoculars. After hiking cross-country for half a mile through thick terrain, Della Ferrera arrived at the site and photographed it, sending the images to Cristiano Dal Sasso, a paleontologist at the Natural History Museum of Milan, whom he knew from earlier collaborations.
Scientists have now confirmed that Della Ferrera has uncovered the largest dinosaur track site in the Alps. The footprints date back 200 million years to the late stages of the Triassic Period, a time when the Italian region of Lombardy had a tropical climate and bordered the Tethys Ocean with tidal flats stretching for hundreds of kilometers. Over the course of millions of years, the same tectonic forces that lifted the Alps tilted this ancient sedimentary layer upright.
The dinosaur tracks are in the Italian Alps and difficult to reach. Photo: courtesy Natural History Museum of Milan.
Roughly 90 percent of the tracks belong to prosauropods, a group of robust, long-necked herbivores who were ancestors of the brontosaurus. Researchers have compared the section of footprints to reading the pages of a book of stone with initial investigations carried out in late autumn already offering insights into the dinosaurs’ behavior.
Most straightforwardly, the tracks can indicate the manner and speed in which the animals walked. In some places, tracks of varying sizes run in parallel suggesting families moving together, possibly on migration or in search of food. In others, the tracks gather together and form groupings, an assembly that has rarely been found across Triassic period discoveries.
Researchers also found tracks that seem to belong to archosaurs, four-legged, crocodile-like reptiles that were the ancestors of the Saltriovenator.
Investigations into the dinosaur tracks will begin in summer 2026. Photo: courtesy Elio Della Ferrera.
“This is now really one of the most important places for Triassic dinosaur footprints,” Dal Sasso said over the phone. “This means we will have to investigate the whole area in the valley [Valle di Fraele] and collect images. Only then can we start to study.”
With the tracks now covered by snow and ice, researchers will have to wait until summer next year to begin the full investigation. There’s time pressure too because the outcrops are vulnerable to erosion. High up on the side of a mountain and with no trails, Dal Sasso said drones will be used to document the site, taking image that will be turned into a 3D replica using photogrammetry.
“For the best-preserved footprints, we can study the number of digits to better determine the animals that produced them,” Dal Sasso said, noting that some will be printed and displayed in a visitor center Stelvio National Park plans to build. “There are many—there are thousands—and this is a rare opportunity.”