意大利阿尔卑斯山脉新发现一处含有大量三叠纪恐龙足迹的遗址，这些保存完好的足迹揭示了约2.1亿年前大型食草恐龙群的活动，为研究恐龙进化提供了珍贵资料。
A newfound site in the Italian Alps holds one of the largest collections of Triassic dinosaur footprints ever seen. About 2,000 fossil footprints appear on this part of the mountain site’s walls, researchers say.
Last September photographer Elio Della Ferrera spotted thousands of dinosaur tracks traversing vertical rock faces in the Fraele Valley of Stelvio National Park, high in the Italian Alps. Some of the prints, spanning as many as 40 centimeters across, date back about 210 million years, making the newly identified site one of the richest deposits of Triassic dinosaur tracks in the world.
The footprints are so well preserved that “it took me a few seconds to realize the photos were real,” says paleontologist Cristiano Dal Sasso of the Natural History Museum of Milan, who is leading the investigation of the site. “Now we can go back in time and study the evolution of dinosaurs in this place.”
In a preliminary study, Dal Sasso and his team deduced that the prints were made by herds of large, herbivorous dinosaurs, probably prosauropods, ancestors of Jurassic sauropods such as Brontosaurus. The tracks formed when dinosaurs walked across muddy tidal flats along the shores of the prehistoric Tethys Ocean, long before the Alps rose.
Studying this newly named “Triassic Park” will be challenging because it is so difficult to access, Dal Sasso says—researchers will have to rely on drones and remote sensing to study and digitally preserve the footprints. Some of the best-preserved fossilized footprints at the newfound site show impressions of the Triassic walkers’ long heels, toes and claws.