A new basal zatracheid temnospondyl from the early Permian Chemnitz Fossil Lagerstätte, central-east Germany

A new zatracheid temnospondyl adds to the fossil-rich T 0 assemblage of the Chemnitz Fossil Lagerstätte (Chemnitz Basin, Sakmarian–Artinskian transition). The skeleton was found in basal air-fall tuffs of the Zeisigwald Tuff (Leukersdorf Formation) and consists of the almost complete skull roof in dorsal view, parts of the occiput, fore and hind limbs, numerous presacral vertebrae and ribs, parts of the pelvic girdle and ventral scales. The new taxon Chemnitzion richteri gen. nov. et sp. nov. is proposed due to the following autapomorphic characters: (1) postorbital skull very short, about five times shorter than the preorbital skull; (2) elongate and robust hindlimbs, with femur length reaching almost half of the skull length. A phylogenetic analysis finds the new taxon at the base of a monophyletic Zatracheidae, forming a trichotomy with Acanthostomatops vorax and the more derived zatracheids [ Zatrachys serratus + ( Dasyceps bucklandi + D. microphthalmus )]. The animal was part of a diverse trophic web of plants, animals and microorganisms. Various vertebrates, arthropods and gastropods constituted a vital community that lived in a dense, seasonally influenced forest habitat dominated by tree-sized ferns, calamitaleans, medullosans and cordaitaleans. The temnospondyl’s death and taphonomic background is closely related to the ash-cloud deposition following a phreatoplinian eruption. The following massive pyroclastic flow finally entombed the moist forest and intensively heated all enclosed organic remnants.