| Autor: |
Kaasalainen U; Department of Geobiology, University of Göttingen, Göttingen, Germany., Heinrichs J; Department of Biology and Geobio-Center, University of Munich (LMU), Munich, Germany., Krings M; Department of Earth and Environmental Sciences, University of Munich (LMU), and Bavarian State Collection for Palaeontology and Geology, Munich, Germany., Myllys L; Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland., Grabenhorst H; c/o Amber Study Group, Geological-Palaeontological Institute and Museum, University of Hamburg, Hamburg, Germany., Rikkinen J; Department of Biosciences, University of Helsinki, Helsinki, Finland., Schmidt AR; Department of Geobiology, University of Göttingen, Göttingen, Germany. |
| Abstrakt: |
One of the most important issues in molecular dating studies concerns the incorporation of reliable fossil taxa into the phylogenies reconstructed from DNA sequence variation in extant taxa. Lichens are symbiotic associations between fungi and algae and/or cyanobacteria. Several lichen fossils have been used as minimum age constraints in recent studies concerning the diversification of the Ascomycota. Recent evolutionary studies of Lecanoromycetes, an almost exclusively lichen-forming class in the Ascomycota, have utilized the Eocene amber inclusion Alectoria succinic as a minimum age constraint. However, a re-investigation of the type material revealed that this inclusion in fact represents poorly preserved plant remains, most probably of a root. Consequently, this fossil cannot be used as evidence of the presence of the genus Alectoria (Parmeliaceae, Lecanorales) or any other lichens in the Paleogene. However, newly discovered inclusions from Paleogene Baltic and Bitterfeld amber verify that alectorioid morphologies in lichens were in existence by the Paleogene. The new fossils represent either a lineage within the alectorioid group or belong to the genus Oropogon. |
