A Glimpse of a Gondwanan Postglacial Fossil Forest

The rooted nature of vegetation allows for individual plants or entire communities to be buried in life position under exceptional geological conditions, thereby preserving their ecology and spatial distribution in the stratigraphic record. Upright lycopsids are not uncommon within paleoequatorial Carboniferous coal-bearing deposits, but they are rare in mid- to high-paleolatitude Gondwana, where they have only been found in lower Permian strata. An exceptionally well preserved in situ Brasilodendron-like lycopsid forest is described from an early Permian postglacial paleolandscape of western Gondwana (Paraná Basin, Brazil). The forest depicted here is unique given its extratropical location, as well as the exceptional preservation of abundant specimens and their morphological and paleoecological aspects. Over 150 lycopsid stumps, with a clustered spatial organization, were mapped. The host succession, overlying glaciomarine diamictites by a few tens of meters, captures the terminal deglaciation in the Paraná Basin, and shows that these forests could establish dense communities on poorly developed soils in postglacial times. Sedimentological data suggest that the death and burial of these lycopsids in life position were caused by crevasse splay progradation over the colonized interdistributary bay areas as a consequence of a major river flooding event.