ORIGINAL PAPER Fossil-Lagerstätte Enspel–a short review of current knowledge, the fossil association, and a bibliography Markus Poschmann & Thomas Schindler & Dieter Uhl Received: 3 September 2009 / Revised: 1 December 2009 / Accepted: 10 December 2009 / Published online: 17 February 2010 # Senckenberg, Gesellschaft für Naturforschung and Springer 2010 Abstract Almost two decades ago, the Generaldirektion Kulturelles Erbe Rheinland-Pfalz initiated annual field cam- paigns in order to investigate geological and palaeobiological aspects of the Fossil-Lagerstätte Enspel, an upper Oligocene crater lake. Since then, the fossil-bearing ‘oilshale’ became more and more exposed due to the removal of the overlying basalt, which is still being commercially exploited. This contribution briefly summarizes the current knowledge that accumulated mainly within the last 20 years, gives a taxonomic listing of the fossil association, and includes a bibliography. Keywords Westerwald . Oligocene . Genesis . Stratigraphy . Taxonomic list . Fossil association Introduction After initial finds of fossil fishes in ‘oilshales’ near the village of Enspel in the Westerwald in the late nineteenth century, this Fossil-Lagerstätte has essentially been forgot- ten for almost a century. It was not until 1986 that fossils were rediscovered by local schoolboys. These fossil plants, insects, fishes, and tadpoles were finally communicated to specialists, and their apparent significance prompted the first scientific excavations and drilling projects at the site around 1990. The results of almost 20 years of research are briefly summarized below. A brief overwiew of current knowledge Geology A first phase of geological research on the Stöffel hill, where the Enspel-Lagerstätte is situated, focused on the commercial usability of what was then termed ‘brown coal’ (von Dechen, 1884; Frohwein 1885; Angelbis and Schneider 1891). In contrast, a second phase of research was exclusively concerned with the occurrence of the basalt (Klüpfel 1929; Lehmann 1930; Ahrens and Burre 1932). After World War II, research concentrated on the importance of basalt as a raw material, but volcanological and stratigraphical aspects were also considered (Ahrens 1960; Nairn 1962). In 1990, initial scientific excavations by the ‘Landesamt für Denkmalpflege/Erdgeschichtliche Denkmalpflege’ (to- day part of the Generaldirektion Kulturelles Erbe RLP) were accompanied by drilling projects that recorded the uppermost meters of the sedimentary succession. Based on these data, aspects of Lagerstätten formation as well as palaeolimnological questions could be addressed for the first time in some detail. It soon became obvious that we are dealing with a small, deep, mesotrophic to eutrophic, meromictic lake with low rates of sediment supply contributing to the formation of black shale, which is This article is a contribution to the special issue “Fossil-Lagerstätte Enspel – exceptional preservation in an Upper Oligocene maar” M. Poschmann (*) Generaldirektion Kulturelles Erbe RLP, Direktion Landesarchäologie, Referat Erdgeschichte, Große Langgasse 29, 55116 Mainz, Germany e-mail: markus.poschmann@gdke.rlp.de T. Schindler Büro für Paläontologie, Stratigraphie und Geotopschutz, Am Wald 11, 55595 Spabrücken, Germany D. Uhl Senckenberg Forschungsinstitut und Naturmuseum, Senckenberganlage 25, 60325 Frankfurt am Main, Germany Palaeobio Palaeoenv (2010) 90:3–20 DOI 10.1007/s12549-009-0017-1