Extending the scope of Darwin's 'abominable mystery': integrative approaches to understanding angiosperm origins and species richness.

Background and aims: Angiosperms are the most species-rich group of land plants, but their origins and fast and intense diversification still require an explanation. Scope: Extending research scopes can broaden theoretical frameworks and lines of evidence that can lead to solving this 'abominable mystery'. Solutions lie in understanding evolutionary trends across taxa and throughout the Phanerozoic, and integration between hypotheses and ideas that are derived from multiple disciplines. Key Findings: Descriptions of evolutionary chronologies should integrate between molecular phylogenies, descriptive palaeontology and palaeoecology. New molecular chronologies open new avenues of research of possible Palaeozoic angiosperm ancestors and how they evolved during as many as 200Myr until the emergence of true angiosperms. The idea that 'biodiversity creates biodiversity' requires evidence from past and present ecologies, with changes in herbivory and resource availability throughout the Phanerozoic appearing to be particularly promising. Conclusions: Promoting our understanding of angiosperm origins and diversification in particular, and the evolution of biodiversity in general, requires more profound understanding of the ecological past through integrating taxonomic, temporal and ecological scopes.