CONICET | Buscador de Institutos y Recursos Humanos

Continuing the study of petrified gymnosperm trunks recovered from the Pedra de Fogo Formation, weidentify here two new taxa from the Permian deposits of the Parnaı´ba Basin, northeastern Brazil. Onetaxon is an endemic form named Ductolobatopitys mussae Conceic¸a?o, Neregato et Iannuzzi, nov. gen., nov.sp., characterized by solenoid, lobed and non-septate heterocellular pith, cauline bundles with endarchmaturation, and secondary xylem with araucarian radial pitting on the tracheid walls. The other form isassigned to the genus Kaokoxylon, which has been recorded from most of Gondwana, including theParnaı´ba Basin, but is recorded for the first time from the Pedra de Fogo Formation with the new speciesKaokoxylon brasiliensis. It is characterized by solid, non-septate heterocellular pith with sclerenchymacells, endarch cauline bundles, and uni-to triseriate radial pitting on the walls of the tracheids. Thesedimentological interpretations of the outcrops where the fossils were collected indicate that theseplants lived on the shores of large continental lakes, with relatively high humidity but possibly periods ofdrought. These inferences are supported by growth interruptions in the secondary xylem, the presenceof calamitalean and tree-fern stems, and microbialites that crop in the same area. These new finds notonly increase the known diversity of the flora in the Pedra de Fogo Formation, but also provide moreaccurate information for understanding the floristic elements that formed the subtropical flora duringthe Cisuralian in this basin in Western Gondwana.