Palaearctic origin and repeated dispersal over the world shaped the biogeographic history of the saprophytic genus Coprinopsis (Psathyrellaceae, Basidiomycota)

Aim: The biogeographic history of most fungi is still poorly known, as well as the patterns and processes responsible for their diversification. Recent studies uncovered that most fungi have originated and present higher diversification rates in the temperate zone. The distributional pattern known for fungi is also different from many plants, animals and microbes. Using the most comprehensive phylogeny of the saprotrophic genus Coprinopsis, we aim to infer the biogeographic history and test evolutionary hypotheses in the genus. LocationWorldwide. Taxon: Fungi, Basidiomycota, Psathyrellaceae, Coprinopsis. Methods: We used a four-gene alignment with 100 species to estimate divergence times using two fossil calibrations within Agaricales. The chronograms were used to estimate diversification rates and geographic state-dependent models were applied. We further reconstructed the ancestral range history of the genus. Results: Molecular dating estimated that the genus has diverged ca. 41 Ma (Eocene) and was originated in the Palaearctic region. Diversification rates showed a decreasing pattern towards the present across Coprinopsis, especially after the Miocene (ca. 14 Ma). The diversification models dependent on distribution showed cosmopolitan lineages with a higher net-diversification rates. When we compared temperate and tropical regions, we found that temperate lineages have higher net-diversification rates. The biogeographic history of Coprinopsis estimated different routes of dispersal. The most common dispersal route was from Palaearctic to the Nearctic (15 times), followed by Palaearctic to the Neotropics (14 times). Main Conclusions: The study is the first to estimate the diversification rates and the historical biogeography of the coprinoid genus Coprinopsis. The diversification dynamics estimates in Coprinopsis are in agreement with the 'generalized diversification rates model', where we found higher diversification rates in temperate regions compared with tropical regions. In general, the ancestral area and major dispersals routes recovered in the genus are similar to findings in other groups of fungi.