Ljupko Rundić

Fish-otoliths from the marine-brackish water transition from the Middle Miocene of the Belgrade area, Serbia

We describe here the first fossil otoliths from the Middle Miocene (Badenian and Sarmatian) of Belgrade, Serbia. They were obtained from Lower Badenian outcrops at Slanci and from upper Badenian and Sarmatian sediments recovered from four shallow wells near the village of Barajevo. The otoliths from the Lower Badenian of Slanci represent fishes typical for an open marine environment, characterized primarily by the mesopelagic families Myctophidae and Bregmacerotidae, a faunal composition that is also well known from other time equivalent locations in the Central Paratethys. The upper Badenian and Sarmatian composition of the fish fauna, in contrast, is dominated by otoliths of the family Gobiidae, indicating a sharp environmental shift from open marine to shallow water, probably slightly brackish environments, which is also confirmed by the faunal composition of mollusks, foraminifera, and ostracods. Most of the gobiid genera identified in the samples from Barajevo represent small fishes of the so-called sand gobies with Ponto-Caspian affinities, such as Economidichthys, Knipowitschia, or Pomatoschistus, or are entirely endemic to the Ponto-Caspian Basin, such as Hyrcanogobius. Another group of endemic Ponto-Caspian gobies is the first fossil record interpreted to represent the genus Proterorhinus. These and other finds currently being investigated indicate that the origin of the extant, rich, endemic gobiid fauna of the Ponto-Caspian Basin dates back to a crucial time in the development of Paratethys during the Middle Miocene when it segregated from the Mediterranean with the onset of phases of low salinity in the basin. In addition, we briefly discuss the distribution of certain gobiid species during Late Badenian and Sarmatian as it begins to emerge. The following new taxa are described based on fossil otoliths: Hyrcanogobius hesperis n.sp. and Proterorhinus vasilievae n.sp.KurzfassungEs werden die ersten fossilen Otolithen aus dem Mittel-Miozän (Badenien und Sarmatien) von Belgrad, Serbien beschrieben. Sie stammen von Aufschlüssen des unteren Badenien nahe Slanci und aus vier Bohrungen nahe Barajevo, in denen oberes Badenien aund Sarmatien durchteuft wurden. Die Otolithen aus dem unteren Badenien von Slanci repräsentieren Fische des offenen marinen Environments, primär charakterisiert durch die mesopelagischen Familien Myctophidae und Bregmacerotidae, eine Faunenassoziation wie sie aus anderen zeitgleichen Lokationen der Zentralen Paratethys gut bekannt ist. Im Gegensatz dazu wird die Fischfauna des oberen Badenien und des Sarmatien dominiert von Otolithen der Familie Gobiidae, die somit einen scharfen ökologischen Wechsel von offen marin zu Flachwasser, möglicherweise sogar Brackwasser, anzeigen, was durch Untersuchungen an Mollusken, Foraminiferen und Ostracoden bestätigt wird. Die meisten der nachgewiesenen Gobiiden-Gattungen in den Proben von Barajevo stammen von den sogenannten „Sand-Grundeln“, die auch heute im Ponto-Kaspischen Raum häufig anzutreffen sind, wie zum Beispiel Economidichthys, Knipowitschia und Pomatoschistus oder sogar endemisch sind, wie Hyrcanogobius. Eine weitere Gruppe endemischer Ponto-Kaspischer Gobiiden ist durch Otolithen der Gattung Proterorhinus vertreten. Zusammen mit anderen, zur Zeit in Bearbeitung befindlichen Funden aus der Paratethys wird deutlich, dass die heutige, reiche, endemische Gobiiden-Fauna des Ponto-Kaspischen Beckens bis in einen Schlüssel-Zeitraum der Entwicklung der Paratethys im Mittel-Miozän zurückreicht, in der sie vom Mittelmeer zunehmend abgetrennt wurde und Phasen reduzierter Salinität einsetzten. Des weiteren wird das sich langsam ergebende Bild der Verbreitung der verschiedenen Gobiiden-Arten im oberen Badenien und Sarmatien der Paratethys kurz umrissen. Zwei neue auf Otolithen basierende Arten werden beschrieben: Hyrcanogobius hesperis n.sp. und Proterorhinus vasilievae n.sp.

Geology of the Čoka structure in northern Banat (Central Paratethys, Serbia)

Geology of the Čoka structure in northern Banat (Central Paratethys, Serbia) The Čoka structure is a fault-bounded anticline in northern Banat, in the southern part of the Neogene Pannonian Basin. The structure and its vicinity were explored by 24 wells. In addition to well logs, paleontological, sedimentological and petrological analyses of cores and 27 seismic sections with different parameters of acquisition and processing were used for geological investigation of the area. The E-SE dipping pre-Neogene basement consists of Lower Triassic clastics and, in the NW part of the study area, Paleozoic greenschists. Thin Middle Miocene (Badenian) sediments unconformably overlie the basement and pinch out towards the elevated NW part of the study area. They are also missing in some wells on the apex of the Čoka structure, probably due to erosion. Badenian sediments were deposited in a shallow marine environment. The late Middle Miocene (Sarmatian) strata are missing and the Badenian is directly overlain by Upper Miocene (Pannonian) sediments. The latter also pinch out towards the NW but in contrast to Badenian sediments, they are present in all boreholes on the Čoka structure. Pannonian deposition took place in a caspibrackish environment of Lake Pannon, with predominance of marls and fine-grained clastics. Pannonian sediments are conformably overlain by latest Miocene (Pontian) and Pleistocene lacustrine, alluvial and terrestrial sediments.

Traces of drilling predation in the Badenian Mollusks from the Rakovica stream (Belgrade, Serbia)

The palaeoecology of fossil molluscs of Serbia is insufficiently studied. Drilling predation indicatesinteractive relationships among Middle Miocene Badenian molluscs from the Rakovicasands. These sands are present in the Rakovica stream valley (southern part of Belgrade),andwell-known data about the fauna has existed since the end of the XIX century. The collectedmaterial (one bulk sample) from the sectionwas used for studies that included 2301 shells ofmolluscs (1617 of gastropods and 684 of bivalves). Among them were specimens with predatorydrill holes. Determining the value of drilling frequency (DF) and prey effectiveness (PE) facilitatesidentification of the relationshipbetween shell-drilling predators and their prey. Basedon analysis of the overall association, carnivorous gastropods were dominantin the sample,comprising more than fifty percent (52.32%) of all gastropod specimens. In addition, they constitutea large percentage of the total sample (43.19%). The largest number of victims was observedamong bivalves, which are indicated by a DF of 16.96%. The results were compared withother localities of Miocene age in Paratethys and with studies on the Miocene sediments fromthe Boreal and the Atlantic Provinces. These comparisons show that PE and DF are very similarto results from the Central Paratethys, but that they are significantly higher than in the other areasmentioned.