Invertebrates from the Lower Permian Bromacker site

The present study describes former and new findings of invertebrates from the Tambach Sandstone Member (Tambach Formation, Rotliegend Group; early Permian) at the Bromacker early tetrapod fossil site near the town Tambach-Dietharz (Thuringian Forest Basin, Free State of Thuringia, central Germany). The Lower Permian of Central Europe is mainly represented by continental sediments, deposited close to the Central Pangaean Mountains on the supercontinent Pangaea. Sand- and siltstones of several fossil sites in the Tambach Formation contain a characteristic fauna and flora, indicating extreme environments caused by a continental near-equatorial climate. During our project “Bromacker”, which runs from 2020 – 2025, we excavated fossils of invertebrates accompanied by vertebrates, plants and ichnofossils within the context of our annual field campaigns at the Bromacker site. The low diverse fauna of invertebrates belongs to the groups of conchostracans, insects, diplopods and Hydromedusae, each containing only 2-4 species, which all need revised descriptions. All these invertebrate fossils are preserved as imprints, no body fossils have been found so far. Most common are conchostracans, whereas insects and diplopods are much rarer. Hydromedusae are less frequent and occur within the Tambach sandstone layers but not within the siltstones of the Bromacker horizon. The invertebrates, dominated by arthropods, are representatives of a typical terrestrial fauna which indicates full continental environments in a strongly seasonal climate causing fluctuating wet and dry conditions with non-permanent ponds and floddings.