Eocene Loranthaceae pollen pushes back divergence ages for major splits in the family

BACKGROUND: We revisit the palaeopalynological record of Loranthaceae, using pollen ornamentation to discriminate lineages and to test molecular dating estimates for the diversification of major lineages. METHODS: Fossil Loranthaceaepollen from the Eocene and Oligocene are analysed and documented using scanning-electron microscopy. These fossilswere associated with molecular-defined clades and used as minimum age constraints for Bayesian node dating using different topological scenarios. RESULTS: The fossil Loranthaceaepollen document the presence of at least one extant root-parasitic lineage (Nuytsieae) and two currently aerial parasitic lineages (Psittacanthinae and Loranthinae) by the end of the Eocene in the Northern Hemisphere. Phases of increased lineage diversification (late Eocene, middle Miocene) coincide with global warm phases. DISCUSSION: With the generation of molecular data becoming easier and less expensive every day, neontologicalresearch should re-focus on conserved morphologies that can be traced through the fossil record. The pollen, representing the male gametophyticgeneration of plants and often a taxonomic indicator, can be such a tracer. Analogously, palaeontological research should put more effort into diagnosing Cenozoic fossilswith the aim of including them into modern systematic frameworks.