New dasycladales and microbiota from the lowermost Valanginian of the Mirdita zone

Abstract

A rich diversified algal microbiota is described from the lowermost Valanginian limestone re?worked in the Upper Cretaceous elastics of the Metohija Cretaceous Unit (Mirdita Zone). Two new dasycladalean taxa are introduced: Zujovicella nov. gen. (type species Suppiluliumaella gocanini Radoicic, 1972) and Furcoporella vasilijesimici nov. sp. Microbiota of this bioclastic limestone (containing dominantly corals and other metazoan fragments) consists of algae, microbial epiliths, microproblematica, foraminifera, calcispongie and a few calpionellids of the Calpionellopsis Zone - Calpionellopsis oblonga (Cadisch), Remaniella cadischiana (Colom), Tinntinopsella carpathica (Murgeanu & Filipescu). Besides the new taxa dasycladales also associated are: Salpingoporella pygmaea (Gumbel), Salpingoporella sp., Gyroporella lukicae Sokac & Velic, Neomerinae and several indetermined taxa. Lithocodium aggregatum (Elliott), other encrusting Lithocodioidea and different microbial epiliths are an important component of this microbiota association. Foraminiferal assemblage consists of: Coscinophragma cf. C. cribrosum (Reuss), Mohlerina basiliensh (Mohler), Nautiloculina bronnimanni Arnaud-Vanneau & Peybernes, Neotrocholina valdensis Reichel, Neo-trocholina sp. Placopsilina sp., Protopeneroplis trochangulata Septfontaine, Trocholina alpina (Leupold), Trocholina delphinensis Arnaud-Vanneau, Boisseau & Darsac, Trocholina sp., lituolids, miliolids and other small benthic taxa. The analyzed lowermost Valanginian limestone originated from the topmost sequence of the Tithonian-Neocomian cycle which ended as a consequence of the Main Cimmerian Events, which occerred, as in the Vardar zone, after the lowermost Valanginian. Cretaceous cycle (Mirdita Crtaceous Unit) begins in the Hauterivian.Opisana su dva nova taksona dazikladalesa: Zujovicella nov. gen. (type species Suppiluliu?maella gocanini Radoicic, 1972) i Furcoporella vasilijesimici nov. sp. iz donjovalendiskog krecnjaka - valutka u gornjokrednim klastitima Metohijske kredne jedinice (Mirdita zona). Prikazana je prateca algalna mikrobiota (Dasycladales, Udoteaceae, Codiaceae), mibrobijski egsliti, mikroproblematika i kalcispongije. U raznovrsnoj i bogatoj bioti ovog valendiskog krecnjaka dominantan je udio korala, inkrustirajucih algi i mikrobialita.U skupini dazikladalesa, pored vise nedeterminisanih vrsta, pomenute su: Salpingoporella pygmaea, Salpingoporella sp., Gyroporella lukicae. Listu foraminifera cine Cosciniphragma cf. C. cribrosum, Mohlerina basiliensis, Nautiloculina bronnimanni, Neotrocholina valdensis, Neotrocholina sp., Placopsilina sp., Protopeneroplis trochangulata, Trocholina alpina, Trocholina delphiensis, Trocholina sp., lituolidi, miliolidi i druge sitne bentoske vrste. Za datiranje ovog valutka najznacajnije su kalpionelide - Calpionellopsis oblonga i Remaniella cadischiana. One ukazuju da je ovaj sedimenat, koji potice iz najmladjih slojeva titon-neokomskog ciklusa, deponovan u najnizem donjem valendisu. Na osnovu ovog podatka zakljucuje se da glavni kimerijski dogadjaji u podrucju Mirdita zone nijesu stariji od najnizeg valendisa. Prema raspolozivim podacima kredni ciklus (Metohijska kredna jedinica) otpoceo je u doba otriva.