Szabó János szerk.: Fragmenta Mineralogica Et Palaentologica 26. 2008. (Budapest, 2008)

FRAGMENTA PALAEONTOLOGICA HUNGARICA 26, BUDAPEST, 2008 Gastropods of the Early Jurassic Hierlatz Limestone Formation; part 1: a revision of type collections from Austrian and Hungarian localities by János SZABÓ Abstract — As first part of a planned series, the major collections of gastropods, published from the Early Jurassic Hierlatz Limestone Formation has been revised taxonomically, and as a result, an up-to-date systematical arrangement is presented below. The revision aims to restore the correct species composition of the type collections first of all, but some suggestions for modifications were also necessary on the levels of different higher categories. Another intention is to gather as much reliable data on the known gastropods from the Hierlatz Limestone into a single publication as possible to provide a better base to continue the exploration of the world of these not really well-known components of the Jurassic biota. The taxonomical errors of the early publications caused also many derived mistakes and uncertainties. Their corrections in this publication will hopefully help to reach more reliable evaluation of these gastropods in different fields of general palaeontology. The number of the distinguished species is 113; most of them belong to formerly known ones, but many new species are established mainly for misidentified or misinterpreted specimens. Several further new species remained in the unlabelled parts of the studied collections, which will be objects of a next publication. The preservation and the accessibility of the originally aragonitic shells are rather bad in the Hierlatz Limestone owing to the characteristically strong rccrystallisation. As consequence, important morphological elements are frequently lacking therefore the recurrent use of the open nomenclature can not be avoided. The new taxa are: Plectotrochus n. gen. (type species: Trocbus pkctus STOLICZKA, 1861), Discohelix pseudomelia n. sp., Discohelix hallstattensis n. sp., Discohelix sima n. sp., Discohelix stolic^kai n. sp., Discohelix tobit^eri n. sp, Asterohelix urkutensis n. sp., Vtychomphalus kericserensis n. sp., Wortheniopsis (Wortheniopsis) urkutensis n. sp., Wortheniopsis (Sisenna) hierlatzensis n. sp., Wortheniopsis (Sisenna) Jancsiin, sp., Wortheniopsis (Sisenna) lokutensis n. sp., Pleurotomaria eplenyensis n. sp., Eaevitomaria danii n. sp., Bathrotomaria martiae n. sp., Eewisiella stolic^kai n. sp., Eewisiella} turbinata n. sp., Crossostoma? schaflwrgensis n. sp., Anticonulus acutus n. sp., Epulotrochus tuberculatus n. sp., Eucyclus (Eucyclus) mitterseensis n. sp., Eucyclus (Eucyclus) sandrae n. sp., Eucyclus (Lokuticyclus) spinnerinensis n. sp., Scaevola? suissenseensis n. sp. Key words — Gastropoda, taxonomical revision, systematics, Early Jurassic, Hierlatz Limestone Formation. SZABÓ, J. (2008): Gastropods of the Early Jurassic Hierlatz Limestone Formation; part 1: a revision of type collections from Austrian and Hungarian localities. — Fragmenta Palaeontologica Hungarica, 26: 1—108. Introduction The Early Jurassic Hierlatz Limestone is one of the most characteristic formations of the Mediterranean Faunal Province in the Tethyan Realm. Its deposition is closely connected to submarine heights, developed during unequal subsidence of former shallow water carbonate platforms in the earliest Jurassic. The accumulation levels may be at the feet of these submarine elevations, on their tops, slopes or in fissures of the sea-bottom at any depth levels. Sedimentation of the Hierlatz Limestone is frequendy episodic and usually full of gaps; it may be also condensed but some accumulations around higher areas have considerable thickness, stratified and more or less continuous. A detailed lithological characterisation of the Hierlatz Limestone Formation is given by VÖRÖS (1991). The palaeontological significance of the Hierlatz Limestone originates from its richness in fossil remains. Gastropods are also common in its associations; sometimes they are abundant and diverse, like in the type locality of the Hierlatz Limestone Formation at Hallstatt (Austria). In contrast, the gastropods are rare or lacking from the contemporaneous lithological types of basin origin. The Hierlatz Limestone is known mainly from Austria and Hungary, but its localities occur also in southernmost Germany, Slovakia, North Italy and Slovenia. It is well-known that many gastropods are good environmental indicators, and extant gastropods also show high degree of provincialism. These two empirical characteristics promise useful conclusions from a thorough study of the gastropod faunas to the reconstruction of the Mediterranean Jurassic palaeoenvironments, and to their history. However, based on the current knowledge of the systematics of the faunas, these evaluations demand many corrections, and then they should be completed with results, coming from new collections. From these, the subsequent pages first of all present the conclusions of a taxonomical revision of the earliest major contributions to the Hierlatz Limestone gastropod palaeontology (HÖRNES 1853, STOLICZKA 1861). Besides, it is necessary to accomplish also a selfrevision of those species that have been identified without a possibility

7 to compare them to the types of the preceding authors by SZABÓ (1979, 1980, 1981, 1982 and 1983) from the Bakony Mts (Hungary). The type collections, some newly discovered museum materials and new specimens from long known and recently discovered Hierlatz Limestone localities contain many gastropod species, which have remained still unknown for science. For these new finds, other systematical publications are planned.