Stránská skála jeskyně: glacialní společenstvo hlodavců (Rodentia) ze staršího středního pleistocenu [Early Middle Pleistocene glacial community of rodents (Rodentia): Stránská skála cave]
Ivan Horáček, Zdeňka Sůvová, Jiří Kučera
A small mammal assemblage from the Stránská skála cave in Brno (about 200 m from the famous section Stránská skála 1) is reported. The assemblage (MNI=175) was obtained from sedimentary infill underlying the surface bone deposit of Ursus deningeri. Although it exhibits structural features typical of Central European assemblages of the Vistualian LGM age (mass predominance of Microtus gregalis, M. arvalis, Dicrostonyx, presence of Lemmus, Citellus, Cricetus, Ochotona, absence of demanding elements, etc.), it shows considerable differences from them. First, some of the respective clades are represented by phenotypic grades (or chronospecies) characteristic of their Late Biharian and/or early Middle Pleistocene populations (Dicrostonyx simplicior, Microtus gregaloides-hintoni, M. arvalidens, M. coronensis phenotypes, etc.). Second, the dominant elements of the assemblage, viz. Microtus gregalis, M. arvalis and M. oeconomus/ratticepodes, examined by detailed morphometric analyses (using a series of metric and non-metric variables) and multivariate comparisons, revealed highly significant differences from the Vistualian populations, and in some stratigraphically significant characters (such AC/L ratio) they are below the range of Vistulian population but conform to those of the Late Biharian populations. For several reasons, contamination of the assemblage seems to be quite improbable. In conclusion, the assemblage from the Stránská skála cave seems to represent a unique record in central Europe, having rather early appearance of a derived community type specialized to pleniglacial conditions. Tentatively, we expect it to come from the early Middle Pleistocene age, supposedly MIS 16 or MIS 12.