The palynological record across the Cretaceous-Tertiary boundary in differing palaeogeographical settings from the southern Pyrenees, Spain

Abstract

North American and Pacific spore-pollen records show a major extinction event at the Cretaceous Tertiary (K-T) boundary, and abrupt changes are similarly found in many marine organisms world-wide. In contrast, records from the Old World reveal little evidence of terrestrial vegetational change across the boundary. In order to improve the characterization of changes across the K-T boundary, palynological assemblages from two sections in the southern Pyrenees have been evaluated. The abundance and diversity of trilete fern spores are high in Maastrichtian samples and show a statistically significant decrease during the Danian. The 'fern spike' of low-diversity spores found elsewhere is not recorded in the Pyrenean region. Minor replacements of taxa across the K-T boundary are also noted, as well as an increase in inaperturate gymnosperm pollen in the Danian. Comparing our two examined sections with one another reveals important differences in angiosperm pollen composition.