LAUSR

Abstract The former lignite pits of the Geiseltal in Saxony-Anhalt, Germany, were an important source of well-preserved Eocene animal and plant fossil remains, including resinites (fossil resins) from different botanical sources. We studied three different types of resinites with distinct morphological characteristics, collected at one of the Geiseltal pits, elucidated their molecular composition and identified the main biomarker and natural product compounds. The excellent preservation of molecular markers in the resinites, not yet consolidated to amber despite their middle Eocene age, allowed us to perform chemotaxonomic assignments by correlation with the natural product compositions of extant plant resins. The results showed that the main botanical contributors to the Geiseltal paleoenvironment were conifers of the Cupressaceae family, pointing to the genus Taxodium by the major presence of chamaecydin, ferruginol, 7α-p-cymenylferruginol and taxodione. The compositions found for two other Geiseltal resinite types suggested an angiosperm origin, compatible with the Burseraceae family and the genera Shorea or Hopea of the Dipterocarpaceae as botanical sources. The results support that this Eocene paleobiome was a semitropical swamp and provide new data for the diagenetic routes of terpenoid natural products.