When the moler (a type of clay) was formed app. 55 million years ago, the area was quite different than we know it today. The island Mors did not exist. In stead there was a 200 m deep ocean. The moler was shaped by microscopic alga, also called diatoméer, which grew at sea level. When huge amounts of these alga constantly sank to the bottom, the alga’s digestion created a lack of oxygen on the sea bed for thousands of years. Therefore it is rare to find fossils from the sea bed. However, the other animals such as fish, birds, reptiles and insects were preserved in an impressive quality, because the lack of oxygen in a way conserves the dead animals. Now and then wood and leaves drifted from the forrest areas to the area, which today is Mors. https://www.visitmors.com/ln-int/north-jutland/moler-mors