A plant fossil assemblage of Lycopodiopsis cf. derbyi from the Corumbataí Formation, Paraná Basin, São Paulo State, Brazil

The Permian lycopsid Lycopodiopsis derbyi Renault, 1890 (Lemoigne and Brown 1980 ) Faria et al. ( 2009 ) is an abundant plant that inhabited the margins of the Paraná Basin under semi-arid and sometimes hypersaline environmental conditions of late Permian. Here we study a remarkable and unprecedented assemblage, with stems attributed to Lycopodiopsis cf. derbyi Renault preserved in an outcrop in the Rio Claro municipality, São Paulo State, Brazil. The stems are preserved in the north-south orientation, spreading over a wide area with a massive concentration of overlapping specimens, thus forming a monospecific plant fossil assemblage. The stems are unbranched or dichotomously branching, preserved as compression-impressions and cast. In the preserved assemblage, there are records of at least three different cortical levels which may be associated with Lycopodiopsis cf. derbyi . This record is possibly non-selective. Lycopodiopsis cf. derbyi commonly occurs in the Passa Dois Group, indicating it was an important component of the southwestern Gondwana coastal floodplains flora, which today constitutes São Paulo State and Southern Brazil.