Field-derived fossil plant data can offer a powerful, yet underutilized, tool for refining the chronological framework of late Cenozoic continental sedimentary records, thanks to the integration with molecular-based phylogenetic evidence. In this study, we present new palaeobotanical results from the youngest deposits of the long Pliocene to Early Pleistocene Cervo River succession (NW Italy), with the aim of improving the chronological resolution of this key continental archive. Carpological assemblages from the Buronzo-Colombera site yielded a diverse aquatic flora characterized by the coexistence of extant taxa, some of which display morphologies acquired through recent evolution, and extirpated genera that were widespread in Europe during the Neogene ( Brasenia, Euryale, Magnolia, Phellodendron, Symplocos ). The presence of abundant megaspores of the extant water fern Azolla filiculoides agrees with an Early Pleistocene westward immigration process, while morphologically transitional fruits and seeds ( Ranunculus , Stratiotes ) highlight ongoing evolutionary diversification at the onset of the Pleistocene. Biochronological constraints derived from species-level carpological identifications were integrated with magnetostratigraphic data. Reverse polarity detected in both a lower and an upper stratigraphic unit indicates deposition during the Matuyama Chron. The integration of palaeomagnetic results with the stratigraphic ranges of extinct, extirpated, and extant taxa constrains the Buronzo-Colombera deposits to the Calabrian (Early Pleistocene), with strongest support for an early Calabrian age (ca. 1.7-1.5 Ma). Our results indicate the high biochronological potential of carpological assemblages in late Cenozoic continental deposits and demonstrate that their integration with palaeomagnetic data and plant phylogenetic information provides a powerful approach for refining the chronological framework of Plio-Pleistocene successions in Europe.
Martinetto et al. (2026) studied this question.