Klerf Formation
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, comprising greenish and reddish shales, siltstones and sandstones, was first described in 1919 by Rudolf Richter (1881-1957) and reaches a maximum thickness of about 1,300 metres (4,300 ft).[1]
| Klerf Formation | |
|---|---|
| Stratigraphic range: Emsian ~ | |
| Type | Geological formation | 
| Sub-units | Reifferscheid Mb. Altenberg Mb. Unterpreth Mb. | 
| Underlies | Heisdorf Formation | 
| Overlies | Schleiden Formation | 
| Thickness | 1,300 m (4,300 ft) | 
| Lithology | |
| Primary | Siltstone, shale | 
| Other | Sandstone | 
| Location | |
| Location | Eifel | 
| Coordinates | 50°14′48″N 06°27′21″W | 
| Region | Rhineland-Palatinate | 
| Country |  Germany | 
| Type section | |
| Named by | Richter | 
| Location | Willwerath near Prüm | 
| Year defined | 1919 | 
| Coordinates | 50°14′48″N 06°27′21″W | 
| Approximate paleocoordinates | 27.1°S 09.7°E | 
| Region | Eifel | 
| Country |  Germany | 
|  Avalonia with the Proto-Tethys Ocean (3) | |
Depositional environment
    
The siltstone and sandstone formation was deposited in an estuarine to deltaic environment.[2] This was located on the edge of Avalonia bordering the Proto-Tethys Ocean.
Fossil content
    

Apart from the largest arthropod, Jaekelopterus (shown on the left), found in the formation, it also preserved the fish, bryozoa, brachiopod and ostracod remains,[1] the arachnids Devonotarbus hombachensis, Xenarachne willwerathensis,[2] and Mutationella indet. and flora.[3]