Introduction The mining process in the area of the Mecsek Mts. (South West Hungary) dates back at least to the first written record, 1782 (HANTKEN 1878). The mining near the city of Pécs developed on the Li‐ assic coal occurrence. First BEUDANT (1822) re‐ ferred to the plant remains of the formation. The mining area produced thousands of plant remains during the centuries of exploitation (BARBACKA 2011). Most of the material has been processed but there are still questions to be explained, e.g. regarding the very common fern fossils. Ferns are the most variable group in the locality, repre‐ sented by 14 species from five families (BARBACKA 2011). A very interesting group of the macrore‐ mains from the Mecsek area belongs to Osmunda‐ ceae. They can be regarded as living fossils be‐ cause the representatives of this group are known since the Permian in almost completely untrans‐ formed form (TAYLOR et al. 2009). Filogenetic rela‐ tionship is suggested between the recent Todea and the studied Todites genera (SPORNE 1979) while Cladophlebis is treated as a transitional form between the Palaeozoic and recent forms by sev‐ eral authors (ZIMMERMANN 1969). Separation of these two genera was originally based on the lack or presence of sporangia. The result of contempla‐ tion was that the two frond types of the same plant (sterile and fertile) were placed into different genera (HARRIS 1961, VAN KONIJNENBURG‐VAN CITTERT 1996, LOWTHER 1958). This separation was not used consistently through the time that is why HARRIS (1931) found it necessary to describe ster‐ ile and fertile fronds from both genera. On the contrary, different authors have used these names in different ways. The cosmopolitan spread of these plants makes the determination more com‐ plicated because several species were described from all around the world. Geological background The Mecsek Mts. are located in Southern Hungary, in Baranya County. Pécs, the centre of the region was an important place in coal mining, as well as Komló. The Mecsek Coal Formation (HETÉNYI in CSÁSZÁR 1997) comprises Upper Triassic and the e ● Acta Naturalia Pannonica e–Acta Nat. Pannon. 3: 01–10. (2012) 1 ©e‐Acta Naturalia Pannonica, 3 (15.05. 2012), HU ISSN 2061–3911 The remarkable world of the ferns in the Mecsek Coal Formation with special focus on the genera Todites and Cladophlebis (SW Hungary) Emese Réka Bodor & Maria Barbacka Abstract – 191 frond specimens of Todites and Cladophlebis were studied from the Liassic Mecsek Coal Formation. These specimens belong to five species: Todites princeps, T. goeppertianus, Cladophlebis denticulata, C. haiburnensis, and C. roesserti. The study of the palaeogeographic distribution of these species shows that all of them were cosmopolitan in the Jurassic. The lowest range was detected by C. roesserti but that might refer to the fossilisation potential of this fragile species instead of the small dispersal area. The environmental needs of the species were studied on the basis of their co‐occurrence with other plants and the morphological features. Both methods showed that most of the forms lived in a humid, wet environment. T. princeps and occasionally T. goepper‐ tianus tend to grow under moderately disturbed, relatively dry circumstances. Key words – Todites, Cladophlebis, Liassic, Mecsek Coal Formation, Hungary. Authors address: – Emese Réka BODOR, ELTE TTK Department of Palaeontology, Pázmány Peter avenue 1/C H‐1117, Budapest, Hungary, e‐mail: emesebodor@gmail.com – Maria BARBACKA, Botanical Department of the Hungarian Natural History Museum, Pf. 222, H‐1476 Budapest, Hungary, e‐mail: barbacka@gw.bot.nhmus.hu, W. Szafer Institute of Botany PAN ul. Lubicz 46, 31‐512 Kraków, Poland.