Influence of terrestrial sedimentation in Pennsylvanian rocks of Croatia

Sedimentary rocks of Pennsylvanian age outcrop at several regions in Croatia. Most of these rocks were deposited in a marine environment, in different tectonic units: Karst (External) Dinarides, Internal Dinarides and Tisia. Pennsylvanian deposits contain a significant amount of terrestrial debris, related to the uplift of the Hercynian mountain belt and its intense erosion. Remnants of land flora are not common, but are present at almost all localities. The most diverse and the best preserved Pennsylvanian land flora in Croatia was discovered on the Velebit Mt. and in the Lika Region. It was dominated by ferns, pteridosperms and cordaitales. The fossil flora from Banovina is less diverse, with pteridosperms, scarce ferns, horsetails and lycopods. The sporadic occurrence of lycopods and horsetails was reported from the mountains of NW Croatia. In the Gorski Kotar Region only plant detritus was observed. Ferns and pteridosperms from Papuk Mt. were discovered in older, Mississippian deposits. Palaeobotanical data reopen the discussion about the palaeogeographic position of the research areas.</p

Palaeobiogeography of the Late Carboniferous brachiopoda from Velebit Mt. (Croatia)

An abundant and diverse Late Carboniferous brachiopod fauna from Velebit Mt. (Croatia) comprises 63 brachiopod taxa dominated by Productida and Spiriferida. The Spiriferinida, Athyridida, Orthotethida and Rhynchonellata are less common, while the Orthida, Dictyonellida and Terebratulida occur in very small numbers. Brachiopods are mostly preserved as casts and moulds in shales, limestones and sandstones. Associated fusulinid foraminifera and calcareous algae indicate a Kasimovian to Gzhelian age for the brachiopod–bearing deposits. The global biogeographic distribution of brachiopod taxa indicates the probable seaways and brachiopod migration routes, along the Euramerican shelves

Palaeoecology of the Late Badenian foraminifera and ostracoda from the SW Central Paratethys (Medvednica Mt., Croatia)

The quantitative study of microfossil communities from the Late Badenian marls at the Sveta Barbara locality (eastern Medvednica Mt.) enabled reconstruction of three different palaeoenvironments: middle shelf, outer shelf and upper bathyal. The dominant factors influencing the distribution of biota were the deepening of the depositional basin and fluctuations of the oxygenation rate. The outer shelf biota existed under conditions of decreased oxygen levels in bottom water, compared to communities from the middle shelf and upper bathyal environments

Middle and Late Miocene palynological biozonation of the south-western part of Central Paratethys (Croatia)

Middle and Late Miocene palynological biozonation of the south-western parts of Central Paratethys (Croatia) is presented based on organic-walled phytoplankton. Nine characteristic palynozones of regional palynostratigraphic range are recognized, e.g. Early Badenian (Langhian) Cribroperidinium tenuitabulatum (Cte), Badenian (Late Langhian – Earliest Serravallian) Unipontidinium aquaeductum (Uaq), Late Badenian (Early Serravallian)  Cleistosphaeridium placacanthum (Cpl), Sarmatian (Middle and Late Serravallian) Polysphaeridium zoharyi – Lingulodinium machaerophorum (Pzo-Lma), early Early Pannonian s.l. Mecsekia ultima – Spiniferites bentorii pannonicus (MulSpa), middle Early Pannonian s.l. Spiniferites bentorii oblongus (Sob), late Early Pannonian s.l. Pontiadinium pecsvaradensis (Ppe), early Late Pannonian s.l. Spiniferites validus (Sva), and late Late Pannonian s.l. Galeacysta etrusca (Get). As inferred from the regional palynostratigraphic correlation, the signals of two transgressions after the isolation of Paratethys during the Sarmatian are recognised: the first one in the late Early Pannonian, when Mediterranean dinoflagellates migrated into the Pannonian Basin, and the second one in the Late Pannonian, when endemic Paratethyan taxa migrated into the Mediterranean.</p

First record of Acanthuridae (surgeonfish) from the Miocene deposits of the Medvednica Mt.

Middle Miocene deposits at the Dubravica locality in SW Medvednica Mt. (N Croatia) contain various marine fossils, including one tooth of the surgeonfish (Acanthuridae). This is the first such record in Croatia and the second in the wider region, besides the Vienna Basin. The appearance of surgeonfishes in the Paratethys coincides with the Miocene thermal maximum. Their distribution was probably controlled by available reef habitat and their palaeobiogeography and migration routes are yet to be studied.</p

Middle Miocene serial killers: Drilled gastropods from the south-western margin of the Central Paratethys, Croatia

This paper focuses on traces of drilling predation in the middle Miocene gastropod assemblage of the Zaprešić Brijeg locality, Croatia, which provides further insight into the palaeoecology of the south-western margin of the Pannonian Basin System during the Badenian. The analyzed gastropod shells were collected in the first half of the 20th century, and are housed in the Croatian Natural History Museum (CNHM) in Zagreb. The CNHM Zaprešić Brijeg collections contain 11063 gastropod shells, of which 1024 have been identified as drilled (9.3% of the sample), with 633 successfully drilled, 113 unsuccessfully drilled, and 278 multiply drilled shells. The most represented families are Potamididae, Nassariidae, Clavatulidae, Turritellidae, Cerithiidae, Muricidae and Naticidae. The gastropod families Naticidae and Muricidae are recognized as the probable predators based on the shape of the drill holes. Middle Miocene (Badenian) gastropods drilling frequency at Zaprešić Brijeg is 5.72%, which is lower than the recorded Badenian gastropods drilling frequency in the Central Paratethys, while the overall gastropod prey effectiveness from the studied locality (15.15%) is higher than the average of the neighbouring Badenian localities in the Central Paratethys. Among the most represented gastropods at this locality, the highest drilling frequency occurs in the infaunal suspension feeders Turritellidae (14.45%), which mostly show traces of the naticid drilling

Pliocene Alluvial Sediments in the Drava Depression of the Virovitica–Slatina Area, Northern Croatia

Clastic sediments in the vicinity of Virovitica (Northern Croatia) consist of gravels, sands, silt clays and marls. Gravels with discontinuous sheet-like geometry are typical for an alluvial fan system. The most abundant sediment, quartz rich sand, originates from a sandy braided river system. Silt, clays, and marls were deposited in the flood plain. They contain fossil macroflora indicative of moderate climate conditions, including maidenhair leaves (Ginkgo), the presence of which suggests that these sediments were deposited before the Pleistocene glaciation