Vol 480, No 1 (2018)

In the late Miocene deposits in the Taralik–Cher locality (Tuva Republic), fossil remains of a giant mustelid of the genus Eomellivora Zdansky, 1924 have been found. This finding is the first reliable evidence of the Eomellivora inhabiting the modern Russia. Teeth of the Eomelliovra from Taralik–Cher are similar in size to those of E. wimani and E. piveteaui from the late Miocene in Eurasia. The morphology of teeth of the material from Tuva is most similar to that of E. ursogulo; therefore, it is considered a small form of Eomellivora ursogulo. The described finding expands the understanding of diversity, variability, and distribution of representatives of the genus Eomellivora in Asia during the late Miocene.

A mass balance model of phosphorus flow in a system of connected water reservoirs has been developed and used for quantitative assessment of phosphorus budget elements in Lake Baikal and water reservoirs on the Angara River, the only river that drains Lake Baikal.

Here is the first description of the visual organ of Acrotrichis grandicollis, a member of Ptiliidae family that includes the smallest free-living insects. The apposition eyes of A. grandicollis have the acone-type crystalline cone; a fused rhabdom is formed by eight retinula cells and surrounded by primary pigment cells. Secondary pigment cells are located only in the distal part of the ommatidium under the lens. The eye consists of about 50 facets about 12 μm in diameter. The A. grandicollis ommatidium ultrastructure has been compared with that of large Coleoptera. The results obtained enabled us to emphasize the compound eye specific features associated with the small body size.

In the winter periods from 1994 to 2017, the grey partridge average abundance in the steppe zone of the southern Urals was significantly negatively correlated with some meteorological parameters (the snow cover height, precipitations, snow density). At the same time, in the subsequent summer period, these winter parameters (including the mean air temperature) had no influence on the bird number. Indeed, the harsh and snowy winters did not affect the grey partridge abundance in the reproductive period. We believe that migrations from the breeding area or nomadic movements of these birds occurred in the most extreme winters.

Analysis of long-term data on chlorophyll a and total phosphorus concentrations, plankton primary production, organic matter mineralization, and weather conditions in the middle of summer in 2003–2017 revealed eutrophication processes in the Neva River estuary. Weather conditions in the region exerted a strong effect on organic matter prodaction and mineralization processes in the estuary. Rainy and cold summers of the recent years promoted massive development of algae due to increased washout of nutrients from the catchment area, but the rate of organic matter mineralization in the water column was reduced because of low water temperature.

New European pine vole records from the Novgorod, Kaluga, Voronezh, and Belgorod oblasts were studied by sequencing of the mtDNA cytb gene (1143 bp) and by karyotyping (routine staining and G-banding techniques). The results enabled us to summarize chromosome variability of this species throughout Eastern Europe. In the sample studied, two geographically replacing chromosomal forms have been identified: northern, 2n = 54 (Novgorod and Kaluga oblasts), and southern, 2n = 52 (Voronezh and, presumably, Belgorod oblasts). Our data make the boundaries of these two karyoforms in Eastern Europe more precise and testify to intraspecific level of their taxonomic differentiation.