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

Dulai, A.: Taxonomic composition and palaeoecological features of the Early Badenian (Middle Miocene) bivalve fauna of Szob (Börzsöny Mts, Hungary)

can be found in the Hungarian Natural History Museum, Budapest. As this material was collected by several workers during a century between 1848 and 1952, the composition of this collection may be not very representative for the locality. For this reason a new collection was made by the author. This second material is derived by washing from the coarse fraction of 10-12 kg sand collected from the locality. Further on only the bivalves will be discussed here and the taxonomic compositions and the ecological characters of the two collections are compared. Since the classification of bivalves is significantly changed soon after the CSEPREGHY-MEZNERICS (1956) monograph, the detailed systematic position of the species is given below based on the adequate volumes of "Treatise on Invertebrate Palaeontology" (MOORE 1969). Palaeoecological characters and distributions are also given for all species. In some cases the referred literature deals only with the palaeoecological features of the genus or another species of the genus, it is indicated by the words "genus" or "other species". Abbreviations: a: abundance in the museum collection (number of specimens); b: dominance in the museum collection (percentage of specimens); c: abundance in the washed material; d: dominance in the washed material. Class Bivalvia LINNÉ, 1758 Subclass Palaeotaxodonta KoROBKOV, 1954 Order Nuculoida DALL, 1889 Superfamily Nuculacea GRAY, 1824 Family Nuculidae GRAY, 1824 Genus Nucula LAMARCK, 1799 Nucula (Nucula) nucleus (LINNÉ, 1758) - a: 6, b: 0.37, c: 7, d: 0.16. - Palaeoecological characters (BERNASCONI & ROBBA 1993): - life habit: vagile infauna; feeding type: detritus feeder; preferred substrate: mixed bottom; depth range: infralittoral-circalittoral. - Distribution: Early Miocene - Recent (STUDENCKA 1986) Superfamily Nuculanacea ADAMS et ADAMS, 1858 Family Nuculanidae ADAMS et ADAMS, 1858 Genus Nuculana LINK, 1807 Subgenus Saccella WOODRING, 1925 Nuculana (Saccella) fragilis (CHEMNITZ, 1784) - a: 10, b: 0.61. c: 3, d: 0.07. - Palaeoecological characters (DAVITASHVILI & MERKLIN 1966; genus): - life habit: vagile infauna; feeding type: detritus feeder; preferred substrate: mixed bottom. - Distribution: Early Miocene - Recent (STUDENCKA 1986). Nuculana cf. emarginata (LAMARCK, 1819) - a: 1, b: 0.06, c: -, d: -. - Palaeoecological characters (DAVITASHVILI & MERKLIN 1966; genus): - life habit: vagile infauna; feeding type: detritus feeder; preferred substrate: mixed bottom. - Distribution: Early Miocene - Pliocene (BOHNHAVAS 1973).