Lagurus

Abstract: The Polyxenidae in the fauna of the Crimeo-Caucasian region is represented by four species: Polyxenus lagurus (Linnaeus, 1758) (= P. lagurus caucasicus Lignau, 1924, syn. n.), Propolyxenus argentifer (Verhoeff, 1921) comb. n. (= P. trivittatus Verhoeff, 1941, = P. sokolowi Lignau, 1924, both syn. n.), a new species, Polyxenus lankaranensis sp. n., and an undescribed Polyxenus sp. The distributions of all these species in the region concerned are mapped, based on old and new records. A molecular phylogeny based on COI sequences is used to study the relationship within and among the genera Polyxenus and Propolyxenus from Western Europe to the southern Caucasus. The results highlight the presence of a number of undescribed species of Polyxenus across this region.

Abstract: Rodents of the subfamily Microtinae are frequently characterized by the presence of enlarged and modified sebaceous glands in a posterolateral zone of the skin. Within this zone, four sites of special glandular development typify particular genera and subgenera: (1) caudal (Dicrostonyx); (2) rump (Lemmus); (3) hip (Microtus in part); and (4) flank (Synaptomys, Neofiber, Clethrionomys, Aschizomys, Eothenomys, Alticola, Phenacomys in part, Lagurus, Arvicola, and Microtus in part. Flank glands are probably a primitive feature in the subfamily and suggest relationship with Old World cricetines. Correlations are suggested at four taxonomic or evolutionary levels within the Microtinae. At the lowest of these, from population to species, in Microtus greater frequency and development of posterolateral glands occurs in higher latitudes. Throughout the subfamily when present, flank and hip glands are either present in all individuals of a species or of a population, or they are in some degree more frequent or better developed in the older males, suggesting both genetic and androgenic dependence. Glandular structure, variation, and taxonomic distribution are described and probable evolutionary and biological correlations are discussed.

Abstract: During the last decades a considerable amount of data on mammals from Mikulino (=Eemian) deposits of the central and southern parts of the Russian Plain has been produced. Mammuthus primigenius (the early type), Palaeoloxodon antiquus (the advanced form), Arvicola ex gr. terrestris, Eolagurus cf. luteus and Lagurus cf. lagurus characterize this period. The so-called ‘Shkurlatian mammal assemblage’ was distinguished on the basis of a number of Eemian faunas. The age of the mammal localities was established by using various geological and palaeontological evidence, together with the results of palaeomagnetic studies and absolute dating. The evolutionary level of the diagnostic species allows correlations between localities from different parts of the Russian Plain that have varying taphonomical conditions. The mammal- and malacofauna of the Mikulino Interglacial can also be used as a basis for correlations between the Karangat marine strata of the Black Sea and the continental deposits (alluvial sediments of the second terrace of the Sudost’ River and the Salyn phase of the Mezin fossil pedocomplex (see Dodonov et al., this volume). Forest, forest-steppe and steppe zone landscapes have been reconstructed for the central and southern parts of the Russian Plain on the basis of the Eemian faunas.

Abstract: Krotovinas, the burrows of small mammals, are common phenomena in steppe landscapes, and for a long time they have been a major point of discussions about the genesis of Holocene Chernozems. In addition, krotovinas provide a very valuable archive of the biological activities of soil, which is essential when stratigraphical ambiguities are to be solved. Despite this, krotovinas have received little attention within pedostratigraphical research. Using the example of the Upper Palaeolithic excavations Kostienki and Borshchevo in the Middle Russian Steppe an integrative soil scientific approach highlights the importance of burrowing small mammals and of krotovina fillings resulting from both bioturbation and soil erosion in the Late Pleistocene. Based on field and laboratory data of sediments inside and outside krotovinas and 14C dating results from two sections, this systematic approach demonstrates the high value of the burrow fillings: black and humus-speckled fillings belong to deep burrows of hamsters dating to the period of Early Holocene Chernozem formation at the very beginning of the Preboreal (10–8 ka cal BC). Greyish sediments originate either from Ag–Bg horizons of the “Gmelin soil” (25–22 ka) or from other as yet unknown Late Valdai paleosols; these fillings are the result of the activities of shallow-burrowing lemmings. In addition, burrow fillings have provided optimal material for worms. Also, fossil bones and teeth found within krotovina fillings give new insights into the occurrence of Cricetus cricetus and Lagurus lagurus in this part of the Middle Russian steppe.