Confirmation of Carboniferous clastic swamp communities

Abstract

Tropical lowlands dominated by arborescent lycophytes are the principal foci for our understanding of Carboniferous peat and non-peat accumulating coastal swamps^1,2. Suggested palaeoeco-logical interpretations of various lycophytes and accessory vegetation have been based on transported compression assemblages^3,4 and palynomorphs^5,6, or in situ permineralized peats⁷. Where transported macrodetritus, resulting in compression assemblages, is used to reconstruct past vegetational patterns, taphonomic factors tend to bias the preserved flora^8–11. Taken alone, or out of depositional context, the heterogeneity of an assemblage most probably bears little or no relationship to that of the original contributing communities. Gastaldo⁹ suggests that reconstructions should be based on the autecology of erect in situ plants because, with peats permineralized in situ, precise resolution in time of laterally equivalent vegetation is difficult. Here I document an erect in situ Early Pennsylvanian lycophyte swamp which provides the first confirmatory evidence for previously hypothetical ecological amplitudes.