Trinocladus divnae and montiella filipovici: A new species (Dasycladales, green algae) from the Upper Cretaceous of the Mountain Paštrik (Mirdita Zone)

Abstract

Two new dasycladalean species from the Upper Cretaceous of the Mountain Paštrik, Kukes Cretaceous Unit of the Mirdita Zone are described: Trinocladus divnae sp. nov. is characterized by variable size of the thallus, relatively narrow main axis, typical Trinocladus organization of the laterals and thin calcification limited to the distal part of the thallus which includes a swollen part of secondaries and short tertiaries. Often, the internal portion of the whorls (except sometimes the main stem membrane), tends to dissolve and form dissolution cavities filled with cement. Montiella filipovici sp. nov. is characterized by a primary skeleton made of a thin individual sheath around a fertile ampullae, often obliterated by recrystallization. Four to six laterals, each giving one secondary and one fertile ampulla located on the upper side of the relatively thick short primary lateral. Upper Cenomanian limestone with Cisalveolina fraasi and Trinocladus divnae sp. nov. was deposited immediately before the events that resulted in sea level rising. The middle and upper Cenomanian eustatic-tectonic processes had different effects in the Paštrik shallow water areas, depending on the distance from the basinal part of the Unit. Bathymetric changes in a part of the Paštrik sedimentary area were not significant, even negligible. Montiella filipovici is found in the post-fraasi shallow water sequence, assigned to the ?uppermost Cenomanian-lowermost Turonian (= Whiteinella archaeocretacea Zone p. p.; a short stratigraphic gap, in a part of the area, is noted). Shallow water limestone with Turonian taxa, corresponding to the helvetca Zone, occurs a few meters upward. Supplementary note: the species Cylindroporella parva RADOIČIĆ is transferred in the genus Montiella, the species Permocalculus elliotti JOHNSON is transferred in the genus Trinocladus, while the species Trinocladus bellus YU JING is transferred in the genus Belzungia.