Kieselknollen am Weg, «Dinosauriertatzen»

"Dinosaur eggs"? Silica tubers and pebble cords run through the Helvetic pebble limestone. The silica comes from silica sponges, which found good living conditions in the early Cretaceous period, i.e. at the time of the formation of the pebble limestone, and were able to spread en masse in the shallow shelf sea next to sea urchins.