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] It is part of Alken quarry along with Nellenköpfchen Formation.^[2]

Klerf Formation
Stratigraphic range: Emsian ~409–392 Ma PreꞒ Ꞓ O S D C P T J K Pg N
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 / -27.1; 09.7
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.^[3] This was located on the edge of Avalonia bordering the Proto-Tethys Ocean.

Fossil content

Restoration of J. rhenaniae

Apart from the largest arthropod, Jaekelopterus rhenaniae, found in the formation, it also preserved other eurypterids (Adelophthalmus sievertsi, Parahughmilleria hefteri, Rhenopterus diensti, Pruemopterus salgadoi, Erieopterus sp.),^[4] possible xiphosuran (Willwerathia),^[5] terrestrial arachnids (Devonotarbus hombachensis, Xenarachne willwerathensis),^[6][7] some fish, bryozoa, brachiopod and ostracod remains,^[1] Mutationella indet. and flora.^[8]

See also

• List of fossiliferous stratigraphic units in Europe
• Geology of Germany
• Floresta Formation
• Old Port Formation