Redescription of Seymouria sanjuanensis (Seymouriamorpha) from the Lower Permian of Germany based on complete, mature specimens with a discussion of paleoecology of the Bromacker locality assemblage

Two nearly complete, articulated, mature specimens of the amphibian Seymour ia are described from the Lower Permian Tambach Formation, lowermost unit o f the Upper Rotliegend, of the Bromacker locality in the midregion of the T huringian Forest near Gotha, central Germany. They are assigned to S. sanju anensis, known elsewhere only from the Lower Permian deposits of Wolfcampia n age in the southwestern United States. This confirms an earlier referral of two immature specimens from the same locality to this species. The new s pecimens are unusual in being highly ossified and allow for the first time a complete description of the carpus and tarsus of Seymouria. The Bromacker Seymouria specimens are part of an assemblage that is unique among Lower Permian localities in Europe in its taxonomic composition and i ts depositional environment. The Bromacker vertebrate assemblage includes m any taxa found elsewhere only in the Lower Permian of the United States. Al l are adapted to a highly terrestrial existence, and the herbivore Diadecte s and a closely related diadectid yet to be described are the most abundant forms, accounting for over half the articulated specimens encountered. Car nivorous, pelycosaurian-grade synapsid reptiles are exceedingly rare. Fossils at the Bromacker quarry were preserved near the center of a small, internally drained, Early Permian basin, the Tambach Basin. The vertebrates of this extraordinarily rich quarry are commonly excellently preserved, of ten complete and articulated, and occur almost exclusively in sheet-flood d eposits that were almost certainly responsible for their death and burial w ith little or no transport; only minor attritional processes are evident. R elationships of the paleoenvironments and the biology of the vertebrates of the Bromacker locality based on the stratigraphy, paleontology, sedimentol ogy, and basinal context of the Tambach Formation indicate that the Bromack er assemblage may represent the earliest known and best documented Early Pe rmian example of a truly terrestrial "uplands" ecosystem. It apparently evo lved and maintained itself independent of contemporary, water-based food ch ains that included aquatic and semiaquatic forms.