Together with the collections of the Museum für Naturkunde of the Humboldt-University Berlin, the collections of the Palaeobotanical Section of the Senckenberg Research Institute and Nature Museum in Frankfurt am Main are belonging to the largest and most important collections of their kind in Germany. Moreover, they are of considerable importance on the European and even on the global scale.
A major part of the palaeobotanical collections at Frankfurt is represented by macrofossils which were recovered from the Tertiary of the Rhine-Main-area and its surroundings since the 19th century. This includes the numerous plant remains of the annual Senckenberg excavations in the middle Eocene “oil shale” of the UNESCO World Nature Heritage Site at Messel which are prepared, conserved and studied here. Furthermore, there are extended collections, e.g., from the Pliocene of Frankfurt-Niederrad (so-called “KLärbeckenflora”), the Oligocene Rupelton (“Rupel-Clay”) of Flörsheim am Main, the Oligocene of Münzenberg in the Wetterau (“Blättersandstein” or “Blätterquarzit”) and the Miocene of the Rhenish lignites. The so-called “KLärbeckenflora” has been collected during construction work for the wastewater treatment plant (Klärbecken”) of Frankfurt and is special in the fact that numerous leaves have been completely isolated from the sediment and are kept on glass-slides. More recently, a large collection of Tertiary plant fossils from the Middle West of the USA was acquired by purchase from a private collector.
The Devonian of the Rhenohercynian is another traditional focus of the palaeobotanical collections at Frankfurt. But, major losses of type and reference material to the pioneering publications of Richard Kräusel and Hermann Weyland due to side-effects of the 2nd World War have not yet been replaced by new material. The collection of Josef Hefter from the well-known site of Alken an der Mosel again contributed important Lower Devonian material mainly during the 1960ies. Important acquisitions of the last decades have also added to the collections of upper Palaeozoic plant remains. They are from the upper Carboniferous coal measures of the Ruhr District and the Saar District (collections of Wolfgang Sippel from Hagen-Vorhalle, and Bernd-Arwed Richter from the now abandoned Mine Camphausen, respectively). Furthermore, a lot of material (including well preserved silicified coniferous logs) has been collected by members of the Section from the lower Permian “Rotliegend” of the Wetterau and the Saar-Nahe area.
Plant fossils of Mesozoic age are subordinately represented in the collections at Frankfurt, but there is some material from the upper Triassic (“Keuper”) and Jurassic. More recently, members of the section have collected in the NW-German Wealden facies (Lower Creataceous, Berriasian-Barremian), and a large collection from the Araripe-Basin (Lower Cretaceous, Aptian) has been purchased. The latter includes interesting remains of early angiosperms.
The material which Richard Kräusel collected himself on areas belonging to former Gondwana during his expeditions to southern Africa, India and Brazil is of upper Paleozoic to lower Mesozoic age and includes a great number of specimens of silicified wood.
Less spectacular, but hardly less important are the collections of microscopic slides at Frankfurt. They include the cuticles which formed the base for the monographs of Richard Kräusel, Hermann Weyland and Volker Wilde (Mesozoic, Paleogene and Neogene) and thin sections of fossil wood mainly of upper Palaeozoic and Tertiary age. Furthermore, there are palynological slides, especially from the Palaeozoic (Devonian and Permian) and from the Palaeogene (Messel and the Helmstedt Mining District). The comparative collections of cuticles and pollen from extant plants form an important supplement for comparisons. Last but not least, the collections of nannoplancton as provided by Sigurd Locker, Erlend Matrinin and Carla Müller to the palaeobotanical collections at Frankfurt most probably form the largest collection of their kind in Germany.
Members of the Section started fieldwork in the Paleogene lignite deposits of the Geiseltal and Helmstedt Mining Districts in central Germany in 2000. Over the years a considerable number of sections has been studied, documented and sampled in great detail. As a result thousands of sediment and lignite samples (mostly in a double set) now form a special archive in the collections which is not only used for running projects, but may also serve as a base for future research even when mining has completely finished, most probably in 2017.