My research is focused on all aspects of the diversification of land plants with focus on seed-free land plants such as ferns and liverworts. I am especially interested in macroevolutionary patterns and their link to underlying microevolutinary processes. In my current research I am focusing in particular on the following key questions: - Diversification of land plants through time investigated by integrating new fossil evidence and DNA based divergence time estimates. - Assembly of species diversity and morphological disparity with focus on the “coupling” of the two parameters in the tree of life and its consequences for taxonomic practice - Evolution of polyploidy in ferns - Early divergence of land plant and the consequences of terrestriazation of plants - Cretaceous Terrestrial Revolution and its consequences for plant life today - Accumulation of plant diversity in SE Asia and Eurasia since the late Eocene - Evolution of insect-plant interactions with focus on the widely ignored evidence for fern-insect interactions My research integrates (1) state-of-the-art phylogenetics, (2) exhaustive expertise in plant anatomy and morphology based on the traditional expertise of the 19th and 20th century, (2) cytology, (3) biogeography and phylogeography, (4) taxonomy, (5) fossil evidence, (6) population genetics, and other related research approaches. Macroevolutionary patterns and processes that shaped the patio-temporal distribution of biodiversity with special emphasise on seed-free land plants such as ferns and liverworts. Current research foci comprise studies that aim to elucidate evolvability of plant lineages in the context of morphological disparity, genome structure, polyploidy, reproductive biology, and trophic interactions. The research encompasses phylogenetics including molecular clock analysis and the integration of molecular and morphological evidence, evolutionary plant morphology and anatomy, palaeontology, taxonomy and systematics.

Origin of Land Plants, Genome evolution in non-seed plants, rophic Interactions of insects and plants with focus on non-seed plants