Stephan Clessin

Born in Würzburg on November 13, 1833, and later based in Regensburg, Stephan (often written Stefan) Clessin was a German malacologist and paleontologist. Sources consulted agree that he first served as a military officer and then worked for the Bavarian railways from 1862 onward.

Clessin became known for his studies of both living and fossil mollusks, especially non-marine species. He also worked as an editor of Malakozoologische Blätter and contributed substantially to the long-running Systematisches Conchylien-Cabinet, helping document and classify shell-bearing animals in a way that remained useful to later specialists.

For readers today, his appeal is the mix of precision and curiosity in his work: he belonged to that generation of scholar-naturalists who combined day jobs with serious scientific publishing. His writings sit at the meeting point of natural history, taxonomy, and the close observation of the freshwater world.