Geschichte: After swimming in the river Töss (somewhere after Winterthur and Tössegg, where it flows into the Rhine), I laid down on the mudstone riverbank when I suddenly felt something pointy on the ground. I was able to dig out 2 shark teeth. I began to think about how they got here.
Geologie: These shark teeth must have had a long journey before they ended up in this place. They originate from the sea floor of the Tethys Ocean which existed between 50 and 200 million years ago. During the formation of the Alps, some material of the Tethys Ocean was lifted to high elevations. Eventually, glaciers eroded the material during the Ice Ages and brought it to the lowlands.