A phylogenetic estimation of trophic transition networks for ascomycetous fungi: are lichens cradles of symbiotrophic fungal diversification? - Arnold, A E; Miadlikowska, J; Higgins, K L; Sarvate, S D; Gugger, P; Way, A; Hofstetter, V; Kauff, F; Lutzoni, F (Sys Biol, 2009)