Ewa Świerczewska-Gładysz

Occurrence and paleoecological significance of lyssacinosid sponges in the Upper Cretaceous deposits of southern Poland

Cretaceous lyssacinosid sponges (Hexactinellida) are rare and poorly recognized. This is the first description of lyssacinosid sponges from the Cretaceous of Poland. The sponges (including six species and three types of root tufts) come from the Upper Turonian–Lower Coniacian of the Opole Trough, Upper Campanian of the Miechów synclinorium, and Upper Campanian of the SE part of the border synclinorium. All localities lie southwards of the previous reports, widening thus the paleogeographic distribution of the group within the North European Province. Cretaceous lyssacinosids seem to be a useful tool in paleoecological interpretations. The presence of thin-walled lyssacinosids with root tufts indicates a soft substrate, slow rate of sedimentation, and calm and deeper water conditions.

The trace fossil Lepidenteron lewesiensis: a taphonomic window on diversity of Late Cretaceous fishes

The trace fossil Lepidenteron lewesiensis (Mantell 1822) provides an exceptional taphonomic window to diversity of fishes as shown for the Upper Cretaceous of Poland, in the Middle Turonian–Lower Maastrichtian deposits of the Opole Trough, Miechów Trough, Mazury-Podlasie Homocline, and SE part of the Border Synclinorium. Lepidenteron lewesiensis is an unbranched burrow lined with small fish scales and bones, without a constructed wall. It contains scales, vertebrae, and bones of the head belonging to ten taxa of teleostean fishes: two undetermined teleosteans, six undetermined Clupeocephala, one Dercetidae, and one undetermined euteleostean. The preservation of fish remains suggests that fishes were pulled down into the burrow by an animal, probably by eunicid polychaetes.KurzfassungDas Spurenfossil Lepidenteron lewesiensis (Mantell 1822) ermöglicht einen biostratinomischen Einblick in die Diversität von Fischen, wie Fossilmaterial aus der Oberkreide von Polen zeigt. Es stammt aus dem Mittelturonium bis Untermaastrichtium des südöstlichen Abschnittes der Grenz-Synklinale, dem Opolen-Trog, dem Miechów-Trog und der Masuren-Podlachien-Homoklinale. L. lewesiensis ist ein unverzweigter Grabgang ohne ausgekleidete Wände, dessen Ränder von kleinen Fischschuppen und—knochen gebildet werden. Diese setzen sich aus Schuppen, Wirbel und Schädelknochen von zehn Teleostei-Taxa zusammen und zwar aus zwei unbestimmte Teleosteer, sechs unbestimmten Clupeocephala, einem Dercetidae und einem unbestimmten Euteleostei. Die Erhaltung der Fischüberreste deutet darauf hin, dass die Fische von einem Tier, wahrscheinlich einem Polychaeten der Familie Eunicidae, in den Bau gezogen wurden.

New Cenomanian (Late Cretaceous) Hexactinellid Sponge Species from the Western Ukraine

Abstract The Cenomanian hexactinellid assemblages are relatively rare and are known only from England and France. The phosphatized sponges from the Pokuttian Podillia in western Ukraine seem to be taxonomically the most diverse Cenomanian hexactinellid assemblage known from Europe and the world. Several new hexactinellid taxa (Class Hexactinellida) are described from the Cenomanian of Pokuttian Podillia: Myliusia rakovensis n. sp., Verrucocoelia regularis n. sp., Tretochone cretacea n. sp., Heterochone boguckii, Dunikowskiella nezvyskensis n. gen. n. sp., and Moretiella foliacea n. sp. A new lychniscosidan genus Dunikowskiella is established within the family Callodictyonidae. Until now, genus Moretiella was reported only from the Aptian of Spain and the Albian of France. The extant genera Heterochone and Myliusia are also rare as fossils. Heterochone was known from the Campanian of Germany. Myliusia, noted in the Miocene of Spain, is well documented in Late Cretaceous for the first time. Tretochone was known only from recent times. The sponges studied lived in the shelf sea, shallower than most recent hexactinellids occur.