Footprints of a 100-foot dinosaur have been discovered on the ceiling of a cave in S France.
Though thousands of people have been through this cave, Jean-David Moreau was the first to notice the footprints on the ceiling and identify them as coming from a sauropod = dino in the Brontosaurus family.
Apparently it's not the first time footprints have been found on a ceiling. Here are 3-toed dinosaur prints from a cave in Australia.
This apparently doesn't seem as strange to geologists as it seems to you and me. They have imagined ways that the sandstone could have been washed away by water flowing through the cave, sparing the places where the sandstone was compressed by the footprints.