New insights in the evolution of the liverwort family aneuraceae (Metzgeriales, Marchantiophyta), with emphasis on the genus Lobatiriccardia

Phylogenetic analyses using two fast evolving plastid markers (rps4, trnL-F) reveal the occurrence of the Australasiatic liverwort genus Lobatiriccardia in the Neotropics. Two new species, Lobatiriccardia oberwinkleri and L. verdoornioides are reported from Ecuador. Phylogenetic reconstructions support Lobatiriccardia and Aneura as monophyletic sister groups and do not place Verdoornia as the first branching Aneuracean taxon but rather sister to Aneura and Lobatiriccardia, which is consistent with mycothallus development in Aneuraceae. Subsequently, Aneuraceae, as treated here, include Aneura, Lobatiriccardia, Riccardia, and Verdoornia. Although high levels of genetic structure can be observed among members of the Aneura pinguis complex, current species delimitations are questionable, and detailed analyses of cryptic speciation and biogeographic patterns are needed to understand the evolution of Aneura, with particular attention paid to the non-photosynthetic species Aneura mirabilis. Ancestral state reconstructions suggest an evolutionary trend of female gametangia, and subsequently the sporophyte, moving from a central position on the dorsal side of the thallus (Verdoornia) to a marginal position between thalluslobes (Lobatiriccardia) to a more ventral (quasi latero-ventral) position under the thallus margin (Aneura).