Szabó János szerk.: Fragmenta Mineralogica Et Palaentologica 21. 2003. (Budapest, 2003)

Praechlamys palosus (STOLICZKA, 1861) (Plate IV: 2-3) — P. palosus is characterised by a markedly low umbonal angle (< 90°) as well as by the different ornamentation of the left and right valves (see SZENTE 1996a, 1998). In the Lower Jurassic of the Northern Calcareous Alps this species seems to be confined to the Sinemurian Hierlatz Limestone Praechlamys rollei (STOLICZKA, 1861) (Plate IV: 4-7) — The fauna of the red fissure-filling limestone is predominated by the peculiar species Praechlamys rollei, reported as a frequent form at the Schafberg by STOLICZKA (1861). It seems to be much probable that the syntypes, whose whereabouts is unknown, were also collected from Pliensbachian that can be thus considered as the stratum typicum of P. rollei. Some poorly preserved valves bearing comarginal rugae and doubtfully assigned to P. rollei have been found in the Hierlatz Limestone as well. Praechlamys subreticulatus (STOLICZKA, 1861) (Plate IV: 8—12) — Valves of P. subreticulatus are ornamented by radial plicae, being very variable both in number and strength. It is possible, however, that the "fine phenotype" (Plate IV: 12; see also SZENTE 1996b, pl. 1. fig. 5) represents a different species. P. subreticulatus is the most frequent bivalve species in the Lower Jurassic of the Schafberg, occurring both in the Hierlatz Limestone and the Pliensbachian red limestone. Entolium ? sp. — Some smooth, circular valves yielded by the Pliensbachian red limestone recall Entolium. Their state of preservation, however, does not allow precise identification. Oxytoma (Oxytoma) inaequivalve (J. SOWERBY, 1819) (Plate IV: 13-14) — This widely distributed and variable species is well represented both in the Hierlatz Limestone and the red limestone of the Schafberg. Placunopsis ? sp. (Plate IV: 15) — "Placunopsis numismalis (QUENSTEDT 1856)" has been quoted from the Hierlatzkalk of the Northern Calcareous Alps by STOLICZKA (1861) and SZENTE (1996a) and was synonymized with P. radiata (PHILLIPS, 1829) by SZENTE (1998). In the light of the studies of TODD & PALMER (2002), however, affinities of this form should be revised. Limea (Pseudolimea) sp. — Some incomplete valves, collected from the red limestone, are assigned to Umea (Pseudolimea)

. Gastropods Collection in two lithological types of the studied area yielded also gastropods: the Sinemurian Hierlatz Limestone around the top of Schafberg (railway terminus) and an Upper Pliensbachian, ferro-manganiferous (fissurefilling) limestone. The latter one has been observed in a nearly vertical rocky wall below Schafberg-Spitze, at the WNW side of the Suissensee. Some fallen blocks of similar lithology were found on the west side of the Mittersee, situating in several hundred meters distance SE from the Suissensee along the main structural line. Gastropods of the typical Hierlatz Limestone were rare and extremely fragmentary therefore hardly identifiable. They consisted of only parts of one or two whorls that indicated belonging to Discohelix, Pleurotomarioidea, Trochidae (Proconulinae) and Ataphridae, respectively. The only well-preserved specimen was found amongst STOLICZKA (1861) originals in the Naturhistorisches Museum, Vienna (Discohelix reticulata STOLICZKA, 1861). The ferro-manganiferous limestone and its fallen blocks in the scree, contained a rather well preserved gastropod faunula. They well accomplish STOLICZKA (1861) original Schafberg collection, major part of which is deposited in the Naturhistorisches Museum, Vienna. The original (lectotype) of Eugclus (Eugclus) alpinus STOLICZKA, 1861 and some unpublished, further specimens of unknown collector are kept in the Museum of the Geologische Bundesanstalt, Vienna. The ferro-manganiferous coating and the matrix indicate that the majority of the museum specimens were collected also from the fissure-filling limestones. Most species of the faunal list below occurred in this limestone (except Discohelix reticulata STOLICZKA, 1861 and Pietteia (Trietteia ?) fischen (STOLICZKA, 1861) The matrix around the originals of Pietteia (Trietteia ?) fischen (STOLICZKA, 1861) indicates presence of a third fossiliferous lithological type, consisting mainly of micritic components, but it has not yet been exacdy located. The specimens of good state of preservation from the Schafberg gastropod fauna are figured in Plate V. Palaeoecology — A highly diversified gastropod fauna occurred in the ferro-manganiferous limestone: eleven of the eighteen species are found in single specimens, the remaining ones are represented also by only a few (2-4) shells. The high diversity suggests that they have lived in a stable environment and, because of their relative scarcity, they must have belonged either to the accessorial components of the community(ies) or/and to predator levels. Living pleurotomarioideans are carnivorous, soft-bodied sponges seem to be their most common diet. The diverse pleurotomarioidean species of the studied fauna might have also preyed on sponges and other soft bodied sessile and sedentary animals. Other components of the fauna are most probably herbivorous or omnivorous. Some of the extant relatives of the eucyclid species live in deep water (bathyal or abyssal) biotopes on unconsolidated substrate [Eucyclini in HICKMAN & MCLEAN 1990 — Eucyclinae here: Eugclus (E.) alpinus, Eugclus (Lokutigclus) sp.]. Other members of the family live on hard substrate in intertidal or shallow subtidal region [CHlodontini in HICKMAN & MCLEAN 1990 — Chilodontinae here: Wilsoniconcha ? aff. biplicata (M. GEMMELLARO, 1911)]. These groups seemed to live under similar conditions also