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NOTE: Selected as one of the best papers published in Paleoclimatology Highlights in 2022 (18 papers selected) 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 (Paran´a 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 Paran´a 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. 

The demise of the Late Paleozoic Ice Age has been hypothesized as diachronous, occurring first in western South America and progressing eastward across Africa and culminating in Australia over an ~60 m.y. period, suggesting tectonic forcing mechanisms that operate on time scales of 106 yr or longer. We test this diachronous deglaciation hypothesis for southwestern and south-central Gondwana with new single crystal U-Pb zircon chemical abrasion thermal ionizing mass spectrometry (CA-TIMS) ages from volcaniclastic deposits in the Paraná (Brazil) and Karoo (South Africa) Basins that span the terminal deglaciation through the early postglacial period. Intrabasinal stratigraphic correlations permitted by the new high-resolution radioisotope ages indicate that deglaciation across the south to southeast Paraná Basin was synchronous, with glaciation constrained to the Carboniferous. Cross-basin correlation reveals two additional glacial-deglacial cycles in the Karoo Basin after the terminal deglaciation in the Paraná Basin. South African glaciations were penecontemporaneous (within U-Pb age uncertainties) with third-order sequence boundaries (i.e., inferred base-level falls) in the Paraná Basin. Synchroneity between early Permian glacial-deglacial events in southwestern to south-central Gondwana and pCO2 fluctuations suggest a primary CO2 control on ice thresholds. The occurrence of renewed glaciation in the Karoo Basin, after terminal deglaciation in the Paraná Basin, reflects the secondary influences of regional paleogeography, topography, and moisture sources.