B. Papp szerk.: Studia Botanica Hungarica 32. 2001 (Budapest, 2001)

Hably, Lilla; Zastawniak, E.: Distribution, taphonomy and palaeoecology of Ulmus L. in the Hungarian Egerian

age of mudstone (such as Pomáz with more than 70% mudstone), some a very low proportion (at Pusztaberki 19%), with intermediate values at the other sites. Leaf preservation varies in these localities. It is best where the proportion of mudstone is high with fewer and fewer taxa identifiable as it decreases. The genus Daphnogene is the only taxon which is identifiable even in the most coarse-grained, sandy sediments because its leaves were coriaceous. The genus Ulmus is another taxon which is still recognizable in these layers, but the leaf margin is mostly destroyed, so that recognition is often possible only from the general shape of the leaves, their primary and secondary venation. Complete leaves, having well visible leaf margins, with teeth, were collected at the Pomáz locality. Most of them (almost 200 specimens) belong to Ulmus pyramidalis Goepp., but 9 specimens determined as small-leaved elm, U. cf. minuta Goepp. (HABLY 1994) were also obtained. This second elm species was an accessory element in the flora of Pomáz. The sedimentary conditions in the other fossil localities was not so favourable for fossil plant impressions. In the Eger-Wind brickyard the proportion of mudstone is only 52%, so the conditions for good preservation of leaf impressions are much poorer. From this locality ANDREÁNSZKY (1966) described several types of Ulmus. The present systematic revision confirms the occurrence of three species of elm in this flora: Ulmus pseudopyramidalis Z. Kvacek et Hably, U. pyramidalis Goepp., and U. fischeri Heer (KVACEK and HABLY 1991). Plenty of leaves look complete, but their margin - the most important feature for the determination of Ulmus species - is not clearly visible. In most cases we can observe only some teeth, which are simple or possess an additional small tooth. The leaves of all these species (Ulmus pseudopyramidalis Z. Kvacek et Hably, U. fischeri Heer and U. pyramidalis Goepp.) are easily separable in most of the specimens. The leaves of the first have mostly asymmetric bases, the secondary veins are distinctly arched and widely spaced and they have simple teeth, often with a small additional tooth. The leaves of U. fischeri have a very deeply cordate base and doubly serrate margin. Those of U. pyramidalis have mostly cuneate bases and straight and much more closely set secondary veins, particularly in the upper part of the leaf. They are similar to the leaves of U. pyramidalis Goepp. from the type locality in Sosnica in Poland (GOEPPERT 1855), in which doubly serrate leaf margins are clearly visible. The good state of preservation of the leaves in the Sosnica flora is associated with another type of sediment, a very fine clay. In this locality teeth are clearly visible, in many cases along the whole margin. The specimens from the Eger-Wind brickyard are poorly preserved in the coarse sediments so the leaf margin is not visible along the whole leaf length. The commonest species in this flora are U. pseudopyramidalis Z. Kvacek et Hably (81 specimens) and U. pyramidalis Goepp. (37 specimens).