Geschichte: When I travelled through Dalarna I arrived in Rättvik. According to my geological map, layers from the upper Ordovician should be exposed in that place. About an hour walking distance away from the town, deep in the forest, there is an interesting rock formation in a nature reserve called 'Amtjärnsbrottet'. I was actually looking for Ordovician trilobites – however, I found thousands of crinoids.
Geologie: Crinoids are marine animals (e.g. starfish, sea urchin, sea cucumber) which have existed since more than 500 Million years and their typical habitat is shallow water. This particular geological outcrop contains a layer which is very densely covered with crinoids. Due to a meteorite impact in the late Devonian (377 Million years ago), this rock formation is now exposed in a vertical orientation.