The earliest scientific description of stromatolites: Freiesleben and the Zechstein Limestone

Although it was Kalkowsky (1908) who coined the term “stromatolite”, Freiesleben (1809) and perhaps Hausmann (1805) had described stromatolitic structures a century earlier. They had found them at the top of the Zechstein Limestone of the Upper Permian Zechstein Group around the Harz Mountains. Similar stromatolites have also been found in the Zechstein Limestone of Thuringia where they form the frame-builders of large reefs. They have been known since the middle of the nineteenth century, but were originally misidentified as fossil sponges, stromatoporoids or calcareous algae.