L. Hably szerk.: Studia Botanica Hungarica 22. 1990 (Budapest, 1990)

phic factors, because they were living under the same climatological endowments. The dominant species are seemingly separable according to biotope as swampy, riparian and hillside vegetation. The dominant species of the swampy vegetation was the species Taxodium dubiurn

. Ulmus pyramidalis constituted the riparian forests, while the species of Daphnogene and Laurophyllurn

, as well as Platanus neptuni were the typical plants of the hillsides lying further from the shores. Among the three coenoses, the swampy and riparian ones can be considered as intrazonal ones. It is only the forest composed of Platanus- neptuni Daphnogene div. sp. which can be considered as real zonal assemblage here, distributed on hilly parts already not influenced by soil water. In these latter forests, Platanus neptuni constituted the dominant tree of the forest, building up the foliage level whereas the Daphnogene species occupied the lower foliage level, mainly the bush level. At the higher foliage level we find the species of Laurophyllum as well as Sterculia inhabiting the lower foliage level. Mixed arboreal component of the forest were, apart from these, the evergreen species of Quercus as well as the Sassafras tenuilobatum

, forming a higher foliage level. In the bush level there were.the species of Daph nogene and Debeya hungarica growing, the liana of the forest was the Smilax tataensis

. The palaeogeographical picture can be fairly authentically drawn after the vegetation. At the lower lying riparian regions there were forests of Betula

, on the higher levels, that of Ulmus, Zelkova species formed, further from them, groves of Acer and Juglans were living. The dominant zonal assemblage was composed of a forest of Platanus neptuni - Daphnogene div. sp.

, up till an elevation of 800 m a.s.l. The humidity requirements here were supplied by the precipitation of the subtropical rain forest and not the soil water only, coupled with the humid atmosphere due to frequent rainfalls. Apart from the evergreen laurel-leaf tree forests, there were deciduous species equally present in the forest, similar to the situation observed recently as well. Probably, the species Sassafras was also deciduous, which is known to be of the same character even today, and the type of the vegetation can be defined as subtropical rain forest. The levels of the forest have been presented in the preceding parts, thus they will not be presented here again. Our fossil assemblage contains, however, certain species that were not assigned to vegetation types as yet. Among them, we can associate the genera Rosa and Cornus as well as the family of Leguminosae, on the basis of their recent biotopes, to the sunny (southern) hill-sides. Recently, Cornus and Rosa are encountered at the bush level of sparse forests as well. In the rich bush level of the Oligocène forests, however they seem not to be able to concur with the Lauraceae. The species of Pi nus and Sequoia were probably living at higher level, far from the shore. Remains of Pinus are generally known from higher elevations, Its small individual number in the fossil flora proves that it was transported from relatively distant localities to the place of fossilization

. Overlooking the biotope of the Arctotertiary elements we can see that they probably intruded not into the zonal assemblages but the intrazonal ones, occupying the places that were not favourable for the Palaeotropical elements

. CLIMATOLOGICAL EVALUATION From the climatological point of view we cannot consider the intrazonal assemblages as markers of the dominant climate because they are dependent on edaphic factors. When evaluating the climate, the zonal assemblages must have a decisive part. The dominant species, Platanus neptuni is typically bound to warm periods. Thermophylous elements of the flora comprise the members of the family of Laureaceae, the evergreen Quercus species as well as the Juglans

. The species composition of the forest testifies a subtropical climate. The humidity requirement of the plants needs more explanation. During the Lower Oligocène (Tard Clay Formation) there are xerophylous floras encountered.