Mid-Pleistocene pollen types of the Brazilian Atlantic Forest (Colônia, São Paulo, Brazil)

Abstract

We present 146 types of fossil palynomorphs deposited in Mid-Pleistocene sediment in the basin of Colônia, SE Brazil, with the aim of improving our knowledge of past plant diversity of the Atlantic Forest. Morphological description, photographs and ecological information are given for Algae (one type), Bryophyta (one type), Pteridophyte (nine identified and four non-identified types), Gymnosperms (three types), Nymphaeales (one type), Magnoliids (two types), Monocots (nine types) and Eudicots clade (116 types). The most represented botanical families in number of types are Asteraceae, Euphorbiaceae, Fabaceae, Malvaceae, Rubiaceae and Sapotaceae. Our inventory highlights palynomorphs associated with ombrophilous forest physiognomy during the Mid-Pleistocene. We identify key palynomorphs related to modern distribution, such as Araucaria and Podocarpus, both rare in the current vegetation of the Colônia region, while Acaena, Caryocar, and Ephedra are absent. Additionally, moisture-affinity taxa, like Isoetes spores, indicate a lacustrine environment. This catalog will serve as a valuable tool for research extending beyond the Colônia basin to Atlantic Forest palynology broadly.