The Klerf Formation is an Early Devonian (Emsian) formation that includes a Lagerstätte in the Northern Eifel hills, at Willwerath near Prüm, Rhineland-Palatinate, Germany. In it Jaekelopterus rhenaniae, a giant eurypterid was discovered. The Klerf Formation was first described in 1919 by Rudolf Richter (1881-1957).
References
Klerf Formation Wikipedia(Text) CC BY-SA