Early Permian tetrapod ichnofauna from the Intra-Sudetic Basin, SW Poland

Tetrapod footprints from Late Palaeozoic deposits of Poland have been known for 150 years, but are poorly studied. Here we present the first comprehensive analysis of an extensive assemblage of fossil tracks from two artificial outcrops near Tłumaczów in the Polish part of the Intra-Sudetic Basin. Accompanied by conifer macrofloral remains and a few invertebrate traces, all footprints occur in reddish to greyish-brown, fluvio-lacustrine siltstones and sandstones of the Early Permian Słupiec Formation. Based on the study of nearly 120 slabs with tracks and trackways, we discern four distinct types of tetrapod footprints. These are assigned to the ichnotaxa Amphisauropus kablikae (Geinitz and Deichmüller, 1882), Ichniotherium cottae (Pohlig, 1885), Dimetropus leisnerianus (Geinitz, 1863), and Dromopus lacertoides (Geinitz, 1861) that can be referred to seymouriamorph, diadectomorph, “pelycosaurian”-grade synapsid and early sauropsid track makers. The Tłumaczów vertebrate track assemblage represents a typical early Early Permian (Asselian–Sakmarian) ichnofauna. Remarkable features are the dominance of footprints of terrestrially-adapted tetrapods and the relative abundance of diadectomorph tracks supporting interpretation of the fossil-bearing strata as part of an intermontane hinterland basin outside the range of semiaquatic anamniotes.

► First comprehensive analysis of an Early Permian tetrapod ichnofauna from Poland.
► Tracks of seymouriamorphs, diadectomorphs, and early amniotes.
► Predominance of footprints of terrestrially adapted tetrapods.
► Typical early Early Permian (Asselian–Sakmarian) inland vertebrate ichnoassemblage.