Revision of the flora of the late Oligocene lake deposits of Orsberg near Unkel on Rhine (Rhineland-Palatinate, Germany)
Abstract
A complete reinvestigation of historical fossil plant collections made in the 19th century at Orsberg (Rhineland-Palatinate, late Oligocene) and published by C.O. Weber and P.
Wessel (1851-1855) resulted in new interpretations on the fossil flora. Previous morphological and anatomical investigations of leaves and carpological are revised and now complemented leading to the following new combinations of taxa: Laurophyllum hemisphaerium (Roselt & Schneider 1969) comb. nov., Corylopsiphyllum celtifolium (C.O.Weber in P.Wessel & C.O.Weber 1855) comb. nov., Ampelopsis dubia (C.O.Weber 1852) comb. nov., Tetrastigmophyllum betulaeforme (C.O.
Weber 1852) comb. nov., and Alnus rhenana (P. Wessel & C.O.
Weber 1855) comb. nov. Furthermore, the flora is supplemented by new records of Magnolia, cf.
Lithocarpus, Laurus, Hydrangea, ? Cleyera, Ternstroemites, Symplocos and Vaccinioides. Preliminary evaluation of the fossil material suggests two types of taphocoenoses bound to different sedimentary settings: peat forming Glyptostrobus swamp forests within the lignite and a Mixed Mesophytic Forest of the East Asian type buried in the oil shale.