Marine palynology of the Alano di Piave Bartonian–Priabonian Global Stratotype Section and Point, NE Italy

Abstract. Further strengthening the multidisciplinary stratigraphic and paleo-environmental analysis of the Global Stratotype Section and Point (GSSP) Bartonian–Priabonian boundary of the Alano di Piave section (NE Italy), here, we present a data report of a highly resolved, quantitative marine palynological study emphasizing organic walled dinoflagellate cysts (dinocysts). The ensuing dataset is interpreted in an exploratory sense through empirical paleo-ecological grouping and spectral analysis. The palynological assemblages are rich, diverse, and well-preserved, dominated by cosmopolitan, open marine dinocyst taxa, indicating a persistently distal, open marine depositional setting. Overall, the assemblages are remarkably stable, with no significant biotic reorganization recorded across the GSSP level. Evident paleo-environmental change is linked to the Middle Eocene Climatic Optimum (MECO) and its aftermath, where a sapropelic interval likely reflects a pluvial phase with enhanced runoff. Spectral analysis reveals that the influx of marginal marine dinocysts is strongly paced by the 400 kyr long eccentricity cycle. This suggests that orbital-scale climate changes, likely related to monsoonal intensity and runoff, controlled sediment transport from proximal settings. This data report includes the formal description of one new genus (Bujakidinium gen. nov.) and four new species (Impagidinium gedlii sp. nov., Guersteinia châteauneufii sp. nov., Guersteinia? sluijsii sp. nov., and Bujakidinium umbellum gen. et sp. nov.). In addition, we provide an extensive taxonomic list with annotations and 18 plates with illustrations of the new taxa. A total of 52 additional plates are available in the Supplement. This data report thus provides a robust palynological framework for the Bartonian–Priabonian GSSP and will be the backbone for ensuing, more detailed analyses.