Matskási István (szerk.): A Magyar Természettudományi Múzeum évkönyve 88. (Budapest 1996)

Bajzáth, J.: Plant macrofossils from Hungarian Pleistocene II. Angiospermatophyta in Győrújfalu, West Hungary

level, i. e. between 20-24 m depth. It is proved by the examination of the mollusc fauna (JÁNOSSY & KROLOPP 1994). Nevertheless the great percentage of the Lower-Pleistocene indicator elements of the fauna define the stratigraphical position and age of this assemblage. We examined both the plants and molluscs in same clay boulders. On the basis of our results we can be sure that they originated in one time. According to the literature (WEST 1964) the climate of the Cromerian interglacial was rather temperate than warm and the Tertiary elements did not appear in significant amounts in West Europe. Another possible answer to the question is that these fossils came from the temporary later part of the interglacial cycle when the characteristic species were mixed and lived together. It is confirmed by the existence of coniferous forest. SUMMARY The age of the unique, very rich fossiliferous fauna and flora - layed in the fluvial deposit between 20-30 metres depth - can be assessed in the upper part of the LowerPleistocene (Günz-Mindel, Cromer interglacial). This statement is based on the stratigraphy of the vertabrates (JÁNOSSY 1979) and molluscs (KROLOPP 1983). This layer seems to be very homogeneous biostratigraphically but we can not exclude the redeposition of the sediment on the top level. From the rich fossiliferous macroflora in Győrújfalu various plant communities could be reconstructed. The aquatic, wetland and terrestrial plant communities are very similar to the modern vegetation. Almost the whole vegetation succession can be traced in the catchment area from the eutrophic, open water to the drier and higher flood plain. In the bottom of the backwater the sediment accumulated, and gradually filled the backwater bed. Plants colonized the shallow riparian area. Fen communities occupied the margin of the backwater. As fen peat accumulated the wet habitats became drier and were colonized by trees. The terrestrial, woodland communities, the spruce forest and mixed pine-spruces forest may be younger than the others and grew in later or latest part of the interglacial. After the examination of the great number of driftwoods I can say more about this problem. The aquatic (probably a slowly flowing part of the river, i. e. a backwater) and the shore communities are the following: obligate aquatics (reed-grass-type, submerged communities, floating-leaved communities), fen communities (reed- and sedge swamp communities, the alder swamp forest). On the higher flood plain alluvial hornbeam forest close the vegetation sequences. * * * Acknowledgements -1 wish to say thanks to Z. TÓTH for his photos of the macrofossils. This study was supported by the Hungarian Scientific Research Fund (OTKA 14893).