20.500.12556/DiRROS-17797 Borers and epizoans on oyster shells from the upper Tortonian, Lower Chelif Basin, NW Algeria Vrtalci in epizoji na zgornjetortonijskih ostreidnih lupinah iz Spodnjega Chelif bazena, SZ Alžirija The three oyster lenses of the upper Tortonian of Djebel Touaka site which are described herein contain three species, Crassostrea gryphoides (Schlotheim), Ostrea lamellosa (Brocchi) and Hyotissa squarrosa (De Serre). The density of shell packing between the lenses is dissimilar. Most of the specimens are disarticulated and poorly fragmented; they exhibit a random distribution and orientation, without any distinct sorting. Bioerosion and encrustation are featured on both surfaces of left and right valves. The identified ichnogenera are Entobia (Bronn), Gastrochaenolites (Leymarie, 1842), Caulostrepsis (Clarke, 1908), Trypanites (Mägdefrau, 1932) and Maeandropolydora (Voigt, 1965). Encrusters are scared, represented by juvenile oysters/other bivalves, bryozoans and barnacles. The coexistence of borings on both sides of valves means that they probably occur not only while alive, but they keep happening after death. The oyster beds were deposited in a foreshore to shoreface environment, from the combined action of wave currents and sedimentation rate. Opisane so tri ostreidne akumulacije iz zgornjega tortonija Djebel Touka v Alžiriji. Ostreidne plasti vsebujejo vrste Crassostrea gryphoides (Schlotheim), Ostrea lamellosa (Brocchi) in Hyotissa squarrosa (De Serre). Gostota ostreidnih lupin variira. Večina primerkov je disartikuliranih in nekoliko fragmentiranih. Razporejeni so naključno in brez preferenčne orientacije. Prav tako niso sortirane. Sledovi bioerozije in preraščanja so prisotni na obeh straneh levih in desnih loput. Prepoznani so bili Entobia (Bronn), Gastrochaenolites (Leymarie), Caulostrepsis (Clarke), Trypanites (Mägdefrau) in Maeandropolydora (Voigt). Preraščanja se stojijo iz juvenilnih primerkov ostrig in drugih školjk, mahovnjakov in ciripednih rakov. Hkratna prisotnost izvrtin na obeh straneh lupin pomeni, da je do preraščanj prišlo tudi po smrti ostreidnih školjk. Ostreidne akumulacije so nastale v širšem območju plimovanja in v plitvem podplimskem pasu pod skupnim vplivom valovanja in hitrostjo odlaganja sedimenta. Miocene borings encrustation Entobia Gastrochaenolites Caulostrepsis Trypanites Maeandropolydora foreshore shoreface miocen vrtanje inkrustacija pas bibavice Entobia Gastrochaenolites Caulostrepsis Trypanites Maeandropolydora plitvi podplimski pas true false true Geološki zavod Slovenije Angleški jezik Slovenski jezik Neznano 2024-01-15 10:47:20 2024-01-15 10:47:20 2024-01-16 03:40:57 0000-00-00 00:00:00 2023 0 0 str. 185-198 no. 1 vol. 66 2023 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2023-08-04 56 0016-7789 10.5474/geologija.2023.008 164580099 1859-Article_Text-12342475-2-10-20230804.pdf 1859-Article_Text-12342475-2-10-20230804.pdf 1 BAFB47F87DDBEBED6B93B509C579AA6C 3fdf7072436207d94cc0f53aaeedc394e4ff1ef9ebf06eb70231ad7bfe279c9b ca6b4e52-b38b-11ee-b0d4-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=24156 Geološki zavod Slovenije Geologija 0 0 0