294 Dinosaurs Once Walked on This Wall

Millions of years ago, in the remote limestone landscape of central Bolivia, did dinosaurs have the ability to walk straight up vertical walls? That’s what it would seem from the strange footprints on Cal Orko, a nearly mile-long and 328-foot-tall slab of limestone imprinted with the weaving tracks of 294 distinct dinosaurs, representing at least eight species of the prehistoric beasts.

The 462 trails add up to 5,055 individual prints, the largest and most diverse collection of tracks in the world, and give the illusion that dinosaurs had the ability to walk directly up and diagonally across walls—this one sloping at a 70-degree angle. This is an astonishing proposition when you remember that some of these lumbering creatures weighed more than 100 tons.

As with all too-good-to-be-true mysteries, scientists have a simple explanation for this wall of wonder. The 68-million-year-old remnants of dinosaur feet were pushed upward by tectonic activity. The area, which once hosted a large lake, had an attractive climate that enticed herbivores and then carnivores. The dinosaurs walked across the area’s shoreline in damp weather, leaving their prints. During dry periods, the prints fermented, and when the rain returned, they were preserved under layers of sediment and mud. This process happened repeatedly, resulting in multiple layers of preserved evidence. Later, tectonic rumblings pushed the earth up into a massive vertical slab, and by virtue of its new position, protected it from modern devastation.