Vol 50, No 6 (2016)

The new microorganism Surninia implicata gen. et sp. nov. from the Vendian (Ediacaran) Berezovsky Trough is described. As a result of biological interpretation of the well-preserved remains of microorganisms, they are assigned to the kingdom Fungi.

Geographical and stratigraphical ranges of the bipolar nuculanid bivalves of the genus Glyptoleda is considered. In the Boreal Biogeographical Superrealm, Glyptoleda is only known in the eastern (high boreal) part: in the Novaya Zemlya and Verkhoyansk–Okhotsk provinces. Glyptoleda is recorded for the first time in the Kolyma–Omolon Province. Possibly, the appearance of glyptoleds in the northern Eurasian basins was associated with cooling episodes. A new species, Glyptoleda parenica sp. nov., is described from the Kungurian–Roadian beds of the southeastern framing of the Omolon Massif.

An assemblage of species of the genus Baylea (B. subpenea (Netchaev, 1894), B. vjatkensis Mazaev, 2015, B. praeburtasorum sp. nov., and B. shilovskyi sp. nov.) from the Lower Kazanian Substage (Middle Permian) is described. It is shown that this assemblage is phylogenetically connected with the Late Kazanian species B. rigida Mazaev, 2015, B. foraminata Mazaev, 2015, B. chimbulatiensis Mazaev, 2015, B. nemdaensis Mazaev, 2015, and B. burtasorum (Golowkinsky, 1868). Index species of three stratigraphic intervals are recognized: B. praeburtasorum sp. nov.–B. shilovskyi sp. nov., B. rigida–B. foraminata, and B. burtasorum. The morphology and polymorphism of the studied species are discussed.

The first fossil representative of the genus Isotrilophus Liljeblad (Mordellidae), I. rasnitsyni sp. nov., from the Lower Eocene of the Green River Formation (Colorado) is described. The new species differs from its only congener, I. erraticus (Smith, 1883), in the shape of eye, metepisternum, configuration of temporal angle, lateral edge of the prothorax, and in the length ratio of the prothorax and elytra. The first I. erraticus south of Nicaragua (e.g., in Costa Rica and Peru) are recorded.

A new halfbeak species (Beloniformes, Hemiramphidae), Hyporhamphus tatjanchenkoi sp. nov., is described from the Lower Sarmatian fish-bearing deposits cropping out along the Pshekha River (Northern Caucasus). Comparative osteological analysis of this new fossil and extant representatives of Hyporamphus seem to indicate that Hyporhamphus tatjanchenkoi sp. nov. is in some ways related to the Indo–Pacific species H. affinis (Günther) and H. gamberur (Rüppell).

Modern dolomite stromatolites are found in Cock Soda Lake (Kulunda Steppe) at a salinity of 100–200 g/L and pH of 10. The mineralogical analysis has revealed the presence in the stromatolites of Ca⎯Mg-carbonates of various compositions. The organisms–edificators of the phototrophic community developing in the lake are determined. They are identified as a part of the mineralized biota (cyanobacteria, bacteria, and eukaryotic alga Ctenocladus circinnatus). Morphological and ultrastructural features of exopolysaccharides secreted by cyanobacteria and bacteria dominant in the phototrophic community are characterized. It is shown that polysaccharides secreted primarily by cyanobacteria have the utmost importance for the formation of stromatolites in Petukhovskoe Soda Lake.

A new gall species, Paleogallus kamchaticus, from the Turonian of the Northwestern Kamchatka Peninsula (Russia), located on Compositiphyllum retinerve (Herman) Herman et Kvaček leaves, is described. The gall-forming process and basic principles of fossil galls classification are discussed.