Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 75. (Budapest 1983)

Vörös, A.: Some new genera of Brachiopoda from the Mediterranean Jurassic

ANNALES H1 STORl CO-NATUR ALES MUSEI NATIONALIS HUNGARICI Tomus 75. Budapest, 1983 p. 5-25. Some new genera of Brachiopoda from the Mediterranean Jurassic by A. VÖRÖS, Budapest Abstract — Seven new Jurassic brachiopod genera: Lokutella. Kericserella, Lychnothyris, Securithyris. Papodina. Bakonyithyris and Securina and a new species Lokutella kondai sp. n. are described on the basis of Lower Jurassic material from the Bakony Mts. (Hungary) and from the Southern Alps (Italy). Besides some ancient forms (Devonian to Triassic) the new genera show relationship with late Mesozoic and Cenozoic deep-sea brachiopods. With 21 figures. Introduction — The Jurassic was an important, perhaps the last, flourishing period in the history of the phylum Brachiopoda. After a marked decrease at about the Triassic/Jurassic boundary (during the Rhaetian and Hettangian), the Sinemurian and Pliensbachian times saw an astonishingly rapid diversification. The centre of the "revolution" was the Tethys while the surrounding epicontinental seas gave way to different faunal provinces. So in the Lower Jurassic two important brachiopod provinces existed: a Mediterranean and a NW-European (AGER 1967, VÖRÖS 1977, 1980). Hundreds of species had been described up to the end of the last century from both provinces allocated to the classical, all-enveloping genera "Rhynchonella", "Terebratula" and "Waldheimia". The new wave of taxonomical research, hallmarked by the name of BUCKMAN (1918) resulted in dozens of new generic names for the NW-European faunas. Unfortunately, very few of the Buckmanian genera were based on or applicable to Mediterranean forms (e.g. Pisirhynchia, Prionorhynchia, Linguithyris) while some genuine old Mediterranean generic names (e.g. Apringia and Cirpa by DE GREGORIO) called regrettably little attention before their rejuvenation in the "Treatise" (AGER 1965). In the literature of the Mediterranean Lower Jurassic brachiopods it was customary even during the last decades to use "Rhynchonella" and Terebratula" for everything or to try to force the species into some NW-European genera. The present author having worked for more than ten years on the Pliensbachian brachiopod fauna of the Bakony Mts. (Hungary), also met with the above difficulties. The typically Mediterranean fauna consists of about one hundred species and a considerable part of these cannot be allocated to any known genera. After studiing their internal morphology it appears justified to erect new genera for them. A remarkable aspect of this study is that some of these Mediterranean genera seem to have very ancient relationship back to the Devonian but at least to the Triassic and a few of them have possible descendants known from the Upper Jurassic and Cretaceous deep-sea sediments (Ammonitico Rosso, Chalk) and from the Recent deep-seas. Though these relationships are not fully investigated and proved, a tentative conclusion can be drawn that the "crisis" at the Triassic/Jurassic boundary was more apparent than real involving withdrawal to deeper seas rather than extinction and this refers to the late Mesozoic decline of the phylum too.