Floodplain habitats of braided river systems: depositional environment, flora and fauna of the Solling Formation (Buntsandstein, Lower Triassic) from Bremke and Furstenberg (Germany)

Abstract

The Solling Formation is the most distinctive unit of the Early Triassic Buntsandstein of the epicontinental Central European Basin. The Solling Formation of Bremke and Furstenberg has yielded one of the richest and most diversified plant collections of the Middle Buntsandstein to date, one of the oldest floras in Europe after the end-Permian mass extinction. Based on the plant fossils, the Middle Buntsandstein ecosystem from Bremke and Furstenberg represents not only one of the earliest floras in Europe after the end-Permian extinction but also one of the earliest Triassic occurrences of insect herbivory from any documented flora worldwide and thus provides a rare glimpse into the third pulse of herbivore expansion. Integrated palaeobotanical, palaeontological and sedimentological studies have enabled reconstruction of two different floodplain environmental settings of the Solling Formation, including their vegetation, the plant-insect interactions and revealing how important taphonomy and environmental settings were for the preservation of Middle Buntsandstein plants. At Bremke a levee-crevasse splay complex is reconstructed that tributed into perennial backwsamps and at Furstenberg unconfined subaerial flows formed a sandy aggradational floodplain with ephemeral ponds. A rich plant community was established and became preserved in backswamps and ponds. This suggests that the scarcity of Buntsandstein floras is clearly related to taphonomical processes and not to extreme environmental conditions under arid or semi-arid climates.