European Palaeobotany and Palynology Conference 2026

Keywords: Upper Cretaceous, Tremp Formation, Allueva Formation, Iberian Peninsula, Paleoecology

The Campanian–Maastrichtian interval was a period of significant climatic and environmental changes that profoundly affected flora and fauna worldwide. In the NE of the Iberian Peninsula, this interval is represented at several localities documenting a faunal turnover during the Maastrichtian, though palynological studies remain scarce. In the Maestrazgo domain (Iberian Chain), newly discovered fossil-bearing sites within the middle–late Campanian Allueva Formation represent a continental succession yielding macro- and microbotanical remains alongside a vertebrate fauna dominated by titanosaur sauropods, offering a promising window into Campanian palaeovegetation of Iberia.

The Maastrichtian Tremp Formation (South-Central Pyrenees), one of the few continental records close to the Cretaceous–Paleogene boundary in Europe with solid chronostratigraphical control, has been palynologically studied at three upper Maastrichtian sites (C29r magnetochron). Palynological assemblages are dominated in abundance by Normapolles angiosperms, reflecting regional arboreal communities of Fagales, but show notable differences between localities: older sites reveal Gondwanan influence (Bacumorphomonocolpites), while the younger one shows boreal influence (Aquilapollenites, Sciadopityspollenites), along with greater gymnosperm pollen abundance. These floristic shifts, observed across two distinct palaeoenvironments (a lagoonal transitional system and an alluvial floodplain), may reflect the Latest Maastrichtian Warming Event and subsequent cooling, illustrating the capacity of Iberian plant communities to respond to short-term climatic stress near the end of the Cretaceous.

Funding/Acknowledgements: This work was supported by MICIU/AEI/10.13039/501100011033/ERDF, EU (projects PID2023-148083NB-I00 and PID2024-158833OB-I00), Aragon Regional Government (Group E18_23R Aragosaurus), and Xunta de Galicia (Group GRC-ED431C 2025/52).