Leonardosia langei Sommer (Charophyta, Porocharaceae) from Corumbataí Formation (Guadalupian), Piracicaba, SP, Brazil: First record of an antheridium and of corticated thalli

Abstract

Fossilized portions of a charophyte found in close association with disperse gyrogonites identified as Leonardosia langei Sommer are described. One sample has an antheridium apparently connected to a thallus clearly corticated. Considering the close association and the lack of other carophyte species than L. langei the thalli are thought to belong to this species. The male structure is very rare and is recorded for the first time in L. langei and in the Porocharaceae. The samples consist of compressions/impressions from the Corumbataí Formation (Guadalupian of the Paraná Basin), found in the municipality of Piracicaba, in the Brazilian state of São Paulo. The presence of such algae provides evidence of some of the palaeoenvironmental conditions prevailing during the deposition of the Corumbataí Formation: a low energy environment, probably along the margin of a shallow inland sea not directly connected to the ocean.