Thousands of dinosaur footprints have been discovered in Stelvio National Park, in the central Alps, left around 210 million years ago by herds of large herbivores. The traces, visible on nearly vertical dolomite rock cliffs, form hundreds of meter-long trails and are so well maintained that some bear finger and claw markings. The Lombardy Region and paleontologist Cristiano Dal Sasso of Milan's Natural History Museum jointly made the announcement. "It is a true 'dinosaur valley' stretching for kilometers: the largest site in the Alps and one of the richest worldwide", the expert remarked. "This site was teeming with dinosaurs: it represents an extensive scientific heritage that will require decades of study, particularly because the area is inaccessible by trails, necessitating the use of drones and remote sensing technologies to analyze the tracks". The parallel tracks of the dinosaurs, he noted, "serve as unambiguous evidence of herd movement in synchronized patterns, and there are also indications of more intricate behaviors, such as groups of animals assembled in circles, possibly for defensive purposes". The discovery is attributed to nature photographer Elio Della Ferrera, who was in the Fraele Valley on September 14th to photograph deer and bearded vultures. During the expedition, he observed the emerging footprints, some measuring up to 40 centimeters in diameter, and promptly captured the initial images, which he immediately forwarded to paleontologist Dal Sasso and the Superintendency.