Upper Permian Vertebrate Coprolites from Vyazniki and Gorokhovets, Vyatkian Regional Stage, Russian Platform

摘要: Numerous coprolites have been found in the Vyazniki and Gorokhovets localities of European Russia. Five identified coprolite-bearing horizons occur upper Permian deposits Vyatkian Regional Stage. Coprolites were collected from mudstone with a coprolite breccia-like layer also intraformational conglomerates that deposited floodplain overbank environment. Two morphotypes (A B) are recognized size shape analysis 32 specimens. Morphotype A has long, nonsegmented feces. Smaller, cylindrical or tubular-shaped morphotype B commonly segmented. SEM images matrix show spheres thin-walled vesicles diameters 0.5–4 mm. Electron Micro Probe (EMP) analyses polished thin sections microcrystalline carbonate-fluoride-bearing calcium phosphate small amounts replaced crystal lattice. Optical microscopy EMP investigations iron manganese oxides responsible for elevated concentrations bulk mass coprolites. Other metals (V, Ni) can be associated forming spheroids 3–10 REEs (rare earth elements, U, other trace element suggest significant eolian sediment input to burial environment The scats contain fish scales bones tetrapods (amphibians reptiles). In one large-sized coprolite, fragment therapsid bone was found. Both matched carnivorous taxa within Archosaurus rossicus zone Eastern Europe. bestpreserved specimens they possibly produced by large therapsid, anthracosaur, early archosauromorph predator.