Vörös A. szerk.: Fragmenta Mineralogica Et Palaentologica 15. 1992. (Budapest, 1992)

The studied locality is 1 km east of the village of Lókút in the northern Bakony Mountains (Text-fig. 1). The Lower Sinemurian Pisznice Limestone rests unconformably on the Hettangian shallow sublittoral Kardosrét Limestone displaying a significant facies change. The Pisznice Limestone is a 15 m thick, thinly bedded pinkish-reddish crinoidal limestone. Palaeoecological analysis proved that the examined sequence is resedimented and of basin-margin type (Dulai 1990). On the basis of palaeobiogeographical evaluation, the Mediterranean character of the fauna of the Lókút Hill is unambiguously documented (Dulai 1990). Vörös (1990) characterised the Mediterranean region by 6 Sinemurian taxa (Linguithyris aspasia, Zeilleria venusta, Liospiriferina angulata, Liospiriferina obtusa, Cuneirhynchia cartieri, and the genus Rhynchonellina ). Five of them were identified in the studied material while a form closely related to the remaining one is also present (Zeilleria aff. venusta). The studied material is deposited in the Paleontological Department of the Hungarian Natural History Museum in Budapest. SYSTEMATIC DESCRIPTIONS Phylum BRACHIOPODA Class ARTICULATA HUXLEY, 1869 Order RHYNCHONELLIDA KUHN, 1949 Superfamily RHYNCHONELLACEA GRAY, 1848 Family DIMERELLIDAE BUCKMAN, 1918 Subfamily RHYNCHONELLININAE AGER, 1959 Genus Rhynchonellina GEMMELLARO, 1871 Rhynchonellina suessi GEMMELLARO, 1871 (Pl. I, Fig. 1; Text-fig. 2) 1894 Rhynchonellina suessi GEMMELLARO - Böse: p. 59, pi. 7, figs. 27-29. 1938 Rhynchonellina cf. suessi GEMMELLARO - Dubar: p. 45, pi. 2, figs. 7-8,10,15. 1974 Rhynchonellina suessi GEMMELLARO - Cicardi and Gaetani: p. 359, pi. 29, pi. 30, pi. 31, figs. 1-3. Material: 1 pedicle valve and 4 fragmentary specimens. Dimensions (mm): Specimen M.91.04. (Text-fig. 2) length: 19.2, width: 20.2, thickness: 10.2 (pedicle valve only). Description - External characters: Medium-sized shell, subtriangular in outline. The sides of triangle are straight, the base is probably convex. The anterolateral corners are rounded. The angle between the lateral margins is about 120°. The length and the width are nearly equal while the thickness of pedicle valve is about half of the width. The pedicle valve is convex. The maximum width is located near the anterior margin. The beak is large and erect. The lateral commissures are straight, the anterior one is probably straight, too. There are some growth lines on the shell surface and weak capillation is visible at some places. Internal characters: The internal characters were not studied due to the incomplete preservation.