Az Eszterházy Károly Tanárképző Főiskola Tudományos Közleményei. 1994. Sectio Geographiae.(Acta Academiae Paedagogicae Agriensis : Nova series ; Tom. 21)
Dávid Árpád: Palaeo-occological and palaeo-pathological observations on upper oligocene molluscs (Eger, Hungary)
In associate with these layers, rich flora and fauna can be found here in a good preservation. The strata, that were deposited during the regression of the Upper Oligocene sea, through T. BÁLDI's and his colleauges' activity got into the palaeontological literature as the "Egerian stage" (BÁLDI, T. 1973.) TREATMENT OF THE SUBJECT During the scientific investigations of the comparatively well preserved Molluscan fossils the author has won numerous palaeoecological and palaeopathological observations /DAVID, A. 1987., 1991/. The Molluscan remains had been collected mainly from the "x" layer /Silty fine molluscan sand/ and the "k" layer /Limonitic friable sandstone/. Palaeoecological observations The fact that there are a lot of abraded, deficient, or broken shells and valves among the collected remains indicates a seashore environment. Owing to the surf, the shells of dead or living creatures were knocked to each other and fell to pieces. In this case, the burial was preceedcd by transportation. The embedding was allochtonous. The proximity of the shore is proved by the presence of plant remains, too. Dentalium simplex (Michelotti ) remains belonging to the Scaphopoda class also refer to an allochtonous embedding. They lie parallel with the laminae of the covering stone. After the animals' destruction, the tests must have been drifted into the lower parts of the sublittoral zone by the streaming water. The author has collected shell-fishes in large quantities, which were embedded intact into the sand of the fonner bottom. It signs that they were buried rapidly by the deposition of sand. The animals' decay was caused by the burial, or they were buried immediately after their death at the place where they dwelt. I have studied the same phenomenon in the case of Anadara , Crassatella , Pitar and Polymesoda species. The author could observe oyster-beds which mark littoral and shallow sublittoral environment. The single oysters formed banks by 34
