An atypical fauna in the Lower Devonian Hunsrück Slate of Germany

Abstract

The Hunsruck Slate is a world renowned conservation lagerstatte, stretching SW-NE in a narrow band between the villages of Bundenbach and Gemunden, Hunsruck region, Germany. A great variety of complete Lower Devonian fossils is preserved with their soft parts pyritised due to rapid burial by sediment. The fossils of the Hunsruck Slate outside the narrow band are scarcely known. They represent the normal Situation: quiet low energy Sedimentation. This paper describes this overall “Rhenish” neritic fauna under the heading “atypical”, in contrast to the famous fossils of the conservation lagerstatte. The fauna described here lacks starfishes, mitrates and chelicerates. The paper begins with an overview of the recent relevant literature (stratigraphic position of the Hunsruck Slate, palaeoecology). The slate fossils were collected in two quarries WNW and NE of Bundenbach (Lingenbach and Karschheck, respectively) and most closely resemble that of the Wisper Valley in the Taunus region. Their geologic age is Lower Devonian, early Emsian, Ulmen Substage. Special interest is given to Community structures, rugose corals, bivalves, gastropods, trilobites, conulariids, brachiopods and crinoids. In the systematic part, the crinoidOrthocrinus simplex is redescribed. Also, two new species are introduced: the rugose coralVolgerophyllum karschheckensis n. gen., n. sp., and the crinoidAcanthocrinus spinosus n. sp.