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VÖRÖS & DULAI Conclusions 1. The I Larky Jurassic diversification of the brachiopod fauna of the TR is consistent with the global biotic recovery process after the end-Triassic extinction. The diversity' peak was reached in the Late Sinemurian. The flourishing of the brachiopods was enhanced by local environmental factors. 2. The sudden Early Toarcian disappearance of the brachiopods from the TR was apparently connected to the Tethyan anoxic event. 3. The decreasing diversity and/or absence of brachiopods in the Middle to Late Jurassic is due to the kmited food-supply at the deepening sea-floor, a consequence of the gradual subsidence of the territory of the TR. 4. The minor Bajocian and Tithonian peaks of brachiopod diversity' were related to phases of extensional tectonic movements, which provided diverse niches and hard substratum favourable for the settlement and growth of brachiopods. It is possible that cold seeps contributed to the enrichment of brachiopods by supporting chemosynthetically based communities. 5. Strongly ornamented (ribbed) brachiopods gradually disappeared from the Jurassic brachiopod assemblages of the TR while the smooth forms remained diverse in the Late Jurassic. Adaptation to deeper marine, starving environments may explain the abundance of Pygopidae in the Tithonian of the TR. * * * Acknowledgements — A large part of the Jurassic brachiopod material at our disposal was collected by the workers oi the Hungarian Geological Institute (led by }ózsef KONDA in the 1960's and 1970's); another considerable part of our collection resulted from three field campaigns of the "Dezső LACZKÓ fossil hunters' camp" organized by the Hungarian Narural History Museum for university students. Here we express our thanks to all participants of those operations. Many other colleagues contributed with findings to our brachiopod fauna; here we mention András GALÁCZ, János SZABÓ and Edina WETTSTEIN, whom we are especially indebted to. Thanks are due to Eszter Piroska HANKÓ for taking the brachiopod photographs. The study was supported by the grant T 043325 of the Hungarian Scientific Research bund (OTKA). References AGER, D. V. (1965): The adaptation of Mesozoic brachiopods to different environments. — Palaeogeographj, Palaeoclimatology, Palaeoecology, 1: 143-172. AGER, D. V. (1987): Why the rhynchonellid brachiopods survived and the spiriferids did not: a suggestion. — Palaeontology, 30: 853—857. AJLMÉRAS, Y. & I'A I'RE, PH. (1990): Histoire des brachiopodes liasiques dans la Tethys occidentale: les crises et l'écologie. — Cahiers Université Catholique du Lyon, série scientifique, 4: 1 — 12. BOCKl I, J. (1874): Die geologischen Verhältnisse des südlichen Theiles des Bakony. II. — Annales Institua Geológia Publia Hungariä, 3(1): 1-155. CAMPBELL, K. A. & BoTïïER, D. J. (1995): Brachiopods and chemosynthetic bivalves in Phanerozoic hydrothermal vent and cold seep environments. — Geolog]

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