Evolution of Borsodia (Arvicolidae, Mammalia) in the Villanyian and in the early Biharian. Quaternary International, 1993, vol. 19, pp. 41-45. A.S. Tesakov.

Abstract. Borsodia Janossy and van der Meulen is a genus of rooted voles belonging to the Mimomys group. The genus was a common element of small mammal associations in the Late Pliocene and the beginning of the Early Pleistocene that is in the Villanyian and the Early Biharian a period of about 1.5 Ma. The species of Borsodia were widely distributed in a latitudinal steppic belt stretching from North China to Central Europe. One of most striking morphological trends in the dental evolution of Borsodia was progressing hypsodonty. The rate of hypsodonty increase in Borsodia was not constant. It increased in a way close to exponential, having a period of relatively low rise in the Early Villanyian and a period of accelerated rise in the Late Villanyian and the earliest Biharian. This is interpreted as a reflection of the growing aridization. Late species of Borsodia gave rise to several rootless lagurine species of the modern fauna in a smooth morphological transition.

Small Mammals of the Late Pliocene and Early Pleistocene from the South of Eastern Europe. Stratigraphy. Geological Correlation, 1993, vol. 1, N 3, 92-96. A. S. Tesakov.

Abstract - Small mammals from the reference sections in the south of Eastern Europe were analyzed. Although geologically instantaneous, the replacement of the Pliocene faunas with dominant rooted voles by the Pleistocene faunas dominated by rootless vole species was preceded by a long Pliocene evolution of arvicolides under the conditions of a growingly arid landscape. The beginning of a drastic transformation of small mammal fauna, which is evidenced by the appearance of rootless arvicolids predates the boundary between the Pliocene and the Quaternary.

Chronological relationships of Pliocene deposits in fluviatile plains between Prut and Southern Bug Rivers, Stratigraphy and Geological Correlation, 1995, 3, N 1, pp. 54 - 64. E.A.Vangengeim, M.A.Pevzner, A.S.Tesakov.

Abstract. Deposits of three Pliocene fluviatile plains between the Prut and South Bug rivers were studied in order to reconsider their disputed age determinations and chronological relations. Different ages of these deposits have been established and their correlation with the Eastern Paratethys stratigraphic scale and magnetochronologic and stratigraphic scales of West European continental deposits have been established. The oldest deposits of the Stol' nicheny Formation are dated as the early Kimmerian (magnetic Chron 5). On a continental scale, they are close to the boundary between the Turolian and Ruscinian. The Kuchurgan Gravel is dated as the terminal early and middle Kimmerian (middle part of the Gilbert Chron) and also as the terminal early Ruscinian (MN zone 14). The Karboliya Beds correspond to the late Kimmerian (the end of Gilbert Chron and to the late Ruscinian (MN zone 15).

Evolution of small mammal communities from the south of Eastern Europe near the Plio-Pleistocene boundary. Acta zool. cracov. ,1995, 38(1), 121-127. A.S.Tesakov.

Abstract. Small mammals of the reference sections from the south of Eastern Europe have been analyzed. An attempt is here made to investigate climatic influence on the development of small mammal communities. Faunas dating from 2.8 to 1.6 Ma were subdivided into six formal stages on the basis of the level of hypsodonty of several evolutionary lineages of arvicolids. Analysis of the structure of small mammal communities confirms the existence of a trend towards open landscapes in the region during the Late Pliocene and Early Pleistocene of southern East Europe.

Ruscinian of the territory of the former Soviet Union. Newsl. Stratigraphy, 1996, 33(2), pp. 77-97. M. A. Pevzner, E. A. Vangengeim, I. A. Vislobokova, M. V. Sotnikova, A. S. Tesakov.

Abstract. Stratigraphic succession and position in the magnetochronological scale have been established for 22 reference localities of the Ruscinian mammals situated on the territory of the former Soviet Union (FSU). The oldest faunas (beginning of the MN 14) occur in Western Siberia. In the European part of the former Soviet Union the oldest faunas are correlated with the middle part of the MN 14 zone. Most of the localities belong to the end of zone MN 14 and to the zone MN 15. At the boundary of zones MN 14 and MN 15 changes in quantitative ratios of mammals are observed important faunal event took place within the MN 15 zone. A number of form appeared at this time subsequently underwent intense development in the Villafranchian. East European faunas have much in common with faunas of the Central Europe and Eastern Mediterranean. Faunas of Western Siberia and Northern Kazakhstan were more influenced by Asian centers of evolution.

Evolution of bank voles (Clethrionomys, Arvicolinae) in the late Pliocene and early Pleistocene of eastern Europe. Acta zool. Cracov., 1996, 39,1, pp.541-547. A. S. Tesakov.

Abstract. The morphology and taxonomy of east European Clethrionomys is briefly discussed. Special attention is paid to the increase in hypsodonty of the molars. Two major stages of this process have been detected. The initial one, spanning the Pliocene and earliest Pleistocene, is the stage of accelerated hypsodonty increase. The second, Pleistocene, stage is characterized by near stasis in hypsodonty. The beginning of this stage is interpreted as the origination of the modern dietary adaptations of Clethrionomys.

The evolution of the schmelzmuster of Lagurini (Arvicolinae, Rodentia). Palaeontographica B, 1997, 245, pp. 45-61. W. von Koenigswald & A.S.Tesakov

Abstract. The evolution of the schmelzmuster in lagurine molars shows two phases roughly related to rooted and rootless molars, respectively. In the first phase the shmelzmuster is differentiated and in the second phase partially reduced. Various species of Borsodia represent the first phase. The asymmetrical schmelzmuster is very similar to that of the arvicoline Mimomys lineage but never reached the same quality of enamel types. Stratigraphically the evolution is not synchronous in both lineages. During the second phase the lagurines represented by various genera are somewhat more progressive than Microtus and Arvicola from the Mimomys-group. Kalymnomys, a fossil lagurine from the Mediterranean shows a symmetrical schmelzmuster indicating a very early separation of the lineages within the Lagurini. The schmelzmuster analysis proves to be a very useful additional tool to investigate phylogenetic relationships.

Evolutionary trends in Mio-Pliocene Leporinae, based on Trischizolagus (Mammalia, Lagomorpha). Palaont. Zeitschr., 1997, 71, 1/2, pp.145-153. A.O.Averianov & A.S.Tesakov.

Abstract. New material of Trischizolagus dumitrescuae from Moldova and Ukraine is described. The variation of p3 in Trischizolagus shows the gradual shift of morphotype frequencies from the 'Hypolagus' pattern in Turolian through the mixture of three patterns (including 'Nekrolagus' morphotype) in Early Ruscinian to the dominant 'Alilepus' pattern in the Late Ruscinian samples. These transformations took place parallel to that of the North American Nekrolagus. Probably North American Sylvilagus, Brachylagus, and Romerolagus had an North American origin from Nekrolagus, whereas Eurasiatic and African Oryctolagus, Caprolagus, Nesolagus, and Poelagus could have originated in the Old World from Trischizolagus.

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