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The Dinarides, together with the Albanides and Hellenides, preserve stratigraphic successions derived from the eastern margin of the Adriatic microplate and remnants of ophiolites obducted from the Maliac-Vardar branch of the Neotethys Ocean. The main stages in the Mesozoic geodynamic history are: 1) rifting leading to opening of the Maliac Ocean in the Late Anisian, 2) onset of an east-dipping intraoceanic subduction in the Early-Middle Jurassic and seafloor spreading in a supra-subduction setting (Vardar Ocean), 3) formation of ophiolitic mélanges in trench-like basins, westward obduction of young supra-subduction ophiolites in the Middle-Late Jurassic and accumulation of flysch-type deposits in foreland basins in the latest Jurassic to Early Cretaceous, 4) subaerial exposure of the newly formed nappes followed by middle to Late Cretaceous transgression, and 5) continental collision in the Maastrichtian and Paleogene. On the continental margin, the Middle Triassic to Early Jurassic extension created a complex horstand-graben geometry that is apparent in the stratigraphic record. The present day NW-SE striking tectonic units are in rough accordance with the Mesozoic paleogeography. Hence, the inferred configuration for the most complete SW to NE transect through Montenegro and Serbia is as follows:The Dalmatian Carbonate Platform, the Budva Basin, the High Karst Carbonate Platform, the Bosnian Basin, the Durmitor High, the Lim Basin, the Drina-Ivanjica High, and the deep-marine distal continental-margin domain. We present a short description of the stratigraphy for these tectonic/paleogeographic units and discuss their possible connection with other units of the Dinarides and Hellenides. The field guide focuses on deep-water deposits, in which radiolarians are the crucial tool for dating. We describe the complete Mesozoic succession of the Budva Zone, the Middle Triassic pelagic episode of the High Karst Zone, the Upper Triassic and Jurassic pelagic rocks of the Lim Zone and two localities with radiolarites associated with ophiolites. The largest part of the guide is devoted to the Budva Zone, a deeply rifted trough in the continuation of the Pindos Basin. The Budva Zone with its external location in the Dinaric orogen was a site of continuous pelagic sedimentation from the Middle Triassic to the end Cretaceous. Radiolarites characterize the Middle Triassic, Hettangian–Sinemurian, Aalenian to Tithonian, and Hauterivian–Barremian to lower Turonian ; pelagic limestones prevail in the Upper Triassic, Berriasian–Valanginian and upper Turonian to Maastrichtian. Calcareous turbidites from the adjacent High Karst Carbonate Platform are interstratified in all units and completely replace radiolarites in the Pliensbachian. Pelagic sequences also occur in the High Karst Zone, but are confined to the Middle Triassic syn- and early postrift deposits. A 20 m thick unit of Middle Triassic nodular limestone and radiolarite within shallow-water carbonates is a typical example. More internally, the western Ćehotina Subzone of the Lim Zone records pelagic sedimentation from the Middle Triassic to early Cretaceous, when synorogenic mixed carbonate-siliciclastic deposition began. This zone has been less investigated than the Budva Zone. A 100 m thick Norian to Rhaetian succession of limestone with chert nodules is dated with conodonts. A Callovian-early Oxfordian age of lime free cherts is determined with radiolarians. The Mihajlovići Subzone that may have been part of the Drina-Ivanjica paleogeographic unit shows Triassic shallow-water carbonates and a Jurassic deepening upward sequence ending with Oxfordian radiolarites. The last two field-trip stops show upper Bathonian-lower Callovian radiolarites in an ophiolitic mélange and upper Anisian radiolarites in direct contact with basalt. These ages, obtained in the south-westernmost ophiolite remnants of the Dinarides, agree with previously documented ophiolite ages in the wider region. In comparison with the Southern Alps and the Apennines, pelagic deposits of the Dinarides are characterized by an earlier onset and considerably higher proportions of silica with respect to carbonate throughout the Mesozoic. The Dinaric basins were connected with the central Neotethys, where the high fertility of surface waters enabled radiolarite formation since the oceanisation (Anisian or earlier) until the early Late Cretaceous, when planktonic foraminifera and calcareous nannoplankton began to dominate worldwide.

V zaporedju kremeničnih apnencev in laporjev na Rettensteinu v Severnih Apneniških Alpah je bila najdena ena najbolje ohranjenih in raznolikih spodnjejurskih radiolarijskih združb zahodne Tetide. V 13 radiolarijskih vzorcih je določenih 200 vrst, ki pripadajo 74 rodovom. Dva rodova in 14 vrst je opisanih prvič. To sta rodova Tetractoma n. gen. in Tipiforma n. gen., ter vrste Arcanicapsa spinosa n. sp., Ares rettensteinensis Cifer, Charlottalum austriacum n. sp., Crucella optima n. sp., Hexapyramis ? sphaericus n. sp., Katroma hasta n. sp., Loupanus pliensbachicus Cifer, Pseudoheliodiscus dispinosus n. sp., Pseudoheliodiscus rotaformis n. sp., Tetractoma tollmanni n. gen. n. sp., Thurstonia ? robusta Cifer, Tipiforma missoniae n. gen. n. sp., Tozerium filzmoosense Cifer, and Trexus rotundus n. sp. Zgornjesinemurijska do spodnjepliensbachijska starost je določena z radiolariji in kalibrirana z amoniti, kalcitnim nanoplanktonom in stabilnimi ogljikovimi izotopi. Podana je primerjava z drugimi dobro ohranjenimi in raznolikimi spodnjejurskimi združbami iz območja zahodne Tetide in Pantalase. Obdobje prehoda sinemurija v pliensbachij je obdobje občutnih sprememb v okolju, ki se odražajo tudi v padcu diverzitete in spremenjeni taksonomski sestavi radiolarijskih združb z Rettensteina. Spremembe so bile verjetno posledica zmanjšane produktivnosti radiolarijev v zgornjem delu vodnega stolpca zaradi aridnega podnebja in zato zmanjšane količine nutrientov. Ob koncu sinemurija je bila verjetno povišana slanost, ker je imel bazen zaradi padca morske gladine slabšo povezavo z odprtim morjem. Glede na povečan ali zmanjšan delež v združbah na prehodu med sinemurijem in pliensbachijem se taksoni delijo na občutljive in na neobčutljive na ta okoljski stres. Naselariji katerih delež se v pliensbachiju zmanjša, so monocirtidni, dicirtidni in multicirditni naselariji, medtem ko se delež tricirtidnih naselarijev poveča. Pri spumelarijih se zmanjša delež družin Pantanelliidae, Emiluviidae in Angulobracchiidae, medtem ko se število primerkov v družinah Xiphostylidae in Conocaryommidae poveča. Saturnalidae se množično pojavijo v najvišjem delu sinemurija, kar lahko pomeni, da uspevajo v bolj zaprtih bazenih in so mogoče odporne na povišano slanost. S primerjavo favne z Rettensteina z združbami nahajališč v Mehiki (Baja Californija), Kanadi (Haida Gwaii) in na Japonskem je bilo mogoče prepoznati razlike med združbami različnih biogeografskih provinc. Razlike se izražajo v prisotnosti ali odsotnosti nekaterih taksonov, razlikah v morfologiji radiolarijev nekaterih rodov in diverziteti združb. Moč je prepoznati razlike med območji nizkih in visokih geografskih širin in razlike med Tetido in Pantalaso. Rezultati potrjujejo obstoj tetidine biogeografske province in pantalasine biogeografske province v spodnji juri. A hemipelagic succession of siliceous limestone and marl on Mount Rettenstein in the Northern Calcareous Alps yielded one of the best-preserved Early Jurassic radiolarian assemblages of the Western Tethys. Thirteen radiolarian samples yielded 200 species belonging to 74 genera. Two genera and 14 species are newly described: Tetractoma n. gen., Tipiforma n. gen., Arcanicapsa spinosa n. sp., Ares rettensteinensis Cifer, Charlottalum austriacum n. sp., Crucella optima n. sp., Hexapyramis ? sphaericus n. sp., Katroma hasta n. sp., Loupanus pliensbachicus Cifer, Pseudoheliodiscus dispinosus n. sp., Pseudoheliodiscus rotaformis n. sp., Tetractoma tollmanni n. gen. n. sp., Thurstonia ? robusta Cifer, Tipiforma missoniae n. gen. n. sp., Tozerium filzmoosense Cifer, and Trexus rotundus n. sp. A late Sinemurian to Early Pliensbachian age of the radiolarian assemblages is determined with radiolarians and calibrated with ammonoid data, calcareous nannofossils and stable carbon isotopes. The studied assemblages are compared with other rich and well-preserved Early Jurassic radiolarian assemblages of the Western Tethys and Panthalassa. The Sinemurian-Pliensbachian transition was a period of great environmental changes that are reflected in a considerable diversity drop and changes in relative abundances of the studied radiolarian assemblages. The observed faunal break across the boundary indicates lower surface productivity of radiolarians due to decreased nutrient supply induced by arid climate. An increased salinity connected to sea-level drop is inferred at the end of the Sinemurian. Based on their response, radiolarians are classified into sensitive and insensitive to this environmental stress. Nassellaria whose relative abundances decrease above the Sinemurian-Pliensbachian boundary, are monocyrtid, dicyrtid and multicyrtid Nassellaria, whereas the number of tricyrtid Nassellaria increases. Spumellaria with decreased relative abundances are Pantanelliidae, Emiluviidae and Angulobracchiidae, whereas the number of Xiphostylidae and Conocaryommidae increases. Shortly below the Sinemurian Pliensbachian boundary Saturnalidae are notably abundant they appear to be resistant to or even thrive under increased salinity. With comparing the studied fauna with diverse faunas from Baja California Sur (Mexico), Haida Gwaii (Canada) and Japan, significant differences between biogeographic provinces are recognized. These differences are reflected in the presence or absence of certain taxa, total diversity and by morphological characteristics within some genera. Differences can be observed between low-latitude and mid- to high latitude assemblages, and between the Tethys and Panthalassa. The present results support the existence of the Tethyan biogeographic province and a Panthalassan biogeographic province in the Early Jurassic.