PALEOCLIMATIC AND PALEOECOLOGIC RECONSTRUCTIONS IN WESTERN GONDWANA: THE ROLE OF ARBORESCENT LYCOPHYTES

The present study allowed to the inference that lycophyte arborescent cormophytic communities were important landscape elements in Western Gondwana during the Visean-Serpukhovian (Pseudobumbudendron) / Artinskian-Kungurian (Bumbudendrom, Brasilodendron) interval. They remained dominant in wet lowland associated with coastal plains during the evolution of the Carboniferous Rhacopteris flora and remained dominant even during the development of the Permian Glossopteris flora, as palaeoecological and palaeoclimatic markers. The dispersion of these plants in Western Gondwana was driven by palaeoenvironmental conditions, in addition to climate changes. The Arborescent Cormophytic Lycophyte Complex was related to coastal clastic swamps and silty sandy soils with low nutrients conditions - a stressful habitat for most land plants. The disappearance of the Arborescent Cormophytic Lycophyte Complex in Western Gondwana was possibly related to progressive drying out and the widespread marine transgression at the waning of the Asselian glacial episode. The present data indicates that the introduction and dispersion of arborescent cormophytic-like lycophytes in western Gondwanaland were conducted by interrelated tectonic, ecological and climatic mechanisms.