Dr. Éva Murai szerk.: Miscellanea Zoologica Hungarica 1. 1982 (Budapest, 1982)

Domokos, T.: Morphometrial study of the chronocline of Granaria frumentum (Draparnaud, 1801) (Gastropoda: Chondrinidae)

Morphometrical study of the chronocline of Granaria frumentum (Draparnaud, 1801) (Gastropoda: Chondrinidae) By T. DOMOKOS (Received July 20, 1981) ABSTRACT. Result of a bidmetrical study on older and younger Pleistocene and recent Granaria frumentum are presented. A tendency for growth in shell height (0.6 mm/1 mill, year) was found. Normal distribution of the parameters was found for larger samples sizes and signs indicative of selective impregnation were noted. INTROCUDTION According to SOOS (1959), Granaria frumentum (Draparnaud, 1801) in Hungary can be traced down to the lower Pliocene layers. From the Pleistocene it is known from several localities (ROT AR ID ES, 1931, 1944; HORVÁTH, 1954; SOÓS, 1959; KROLOPP, 1958, 1975, 1976, 1978; DÖVÉNYI, 1973). HORVÁTH (1954) describes it as a common species of the Giinz 1/2 interstadial layer of the classical locality at Paks, at a depth of nearly 41 m. LOZEK (1964), in his comprehensive treatise on the Czechoslovakian Pleistocene, regards the species as frequent in the G/M (Giinz/ Mindel) interglacial

. According to him, it had not become extinct by the beginning of the R/W (Riss/WUrm) interglacial, but during the B (Boreal) and A (Atlanticum) period of the Holocene, together the Chondrula tridens (O.F.Müller, 1874), it was dominant, penetrating up to humid, higher altitude regions. In this paper on the Hungarian Quarternary mollusc fauna, KROLOPP (1973) differentiates 6 faunal phases in the Pleistocene and divides the whole epoch into 14 periods. Using the Alpines System, he found it to be a frequent species in the Praegiinz-Giinz, GiinzMindel interglacials and the Würm I-n interstadial. Nowadays it is found in habitats varying from humid to faintly humid, warm, avarage temperature between 10°C and 15°C (SOÓS, 1959; LOZEK, 1964) and the centre of its range is in the Pyrenees. In Hungary, according to the published fauna catalogue, it lives In higher, more humid areas, and occurs only sporadically in the arid Great Hungarian Plain (PINTÉR, RICHNOVSZKY & S. SZIGETHY, 1979). In Békés county, thoroughly explored by KOVÁCS (1974), it was found in a few localities only. SOOS (1959) considered recent specimens to be variable in size, form and teeth. Based on their experience from research on the Pleistocene mollusc fauna, KROLOPP and LOZ*EK recognize a distinct tendency in the morphosis of Granaria of younger and older layers (KROLOPP'

s pers.comm.). The purpose of this paper is to prove the above and to provide additional data on changes in shell morphology of the species during the last 1 million years. MATERIAL AND METHOD I studied mature specimens with intact mouth from 3 localities of different geological ages. In chronological order: a/ Kocsola - recent: 43 specimens;