Acanthodian biostratigraphy and interregional correlations of the Devonian of the Baltic States, Belarus, Ukraine and Russia

The Lower and Middle Devonian acanthodian research provided for different regions of Russia, Belarus, Ukraine and Baltic States, has shown a various degree of the similarity in the assemblages and biozonation. The Nostolepis minima Zone (early Lochkovian), identified in the Old Red Sandstone, transitional and carbonate facies, allows to correlate the Tilze in Baltic, Borshchov and lower Chortkov in Podolia, Domachevo and Dubitsa in Belarus, lower Khatayakha in Timan-Pechora and Uryum + Tolbat in Taimyr. The late Lochkovian Lietuvacanthus fossulatus acanthodian Zone correlates the Stoniskiai of Baltic and upper Chortkov-Ivane-lowermost Dniester of Podolia. The Naul Formation of Timan-Pechora and Daksan + Yunkhod of Taimyr (Pragian) have yielded the Nostolepis taimyrica, respectively as Varandei and Taribigai + Dolgan (Emsian) - the Nostolepis multangula and Watsonacanthus oervigi zone assemblages. The Rezekne and Pärnu of the Baltic area are related to the Vitebsk and Adrov of Belarus (the Laliacanthus singularis acanthodian Zone), equally as the Vadja and Osveya (Cheiracanthoides estonicus) or Leivu and Gorodok (Ptychodictyon rimosum). The Nostolepis kernavensis Zone based correlation (uppermost Eifelian) is defined for the Kernave in the Baltic, Kostiukovichi in Belarus, Mosolovo and Chernyi Yar in the Central Devonian Field and Lekkeiyaga in Timan-Pechora. The acanthodian based correlation of the Givetian series is less substantiated because of the much rarer finds and interrupted vertical distribution. The Arukula and Burtnieki of the Baltic area (Diplacanthus gravis acanthodian Zone) are supposed analogous to the Staryi Oskol in the Central Devonian Field and the Goryn (lower Polotsk) of Belarus. The Devononchus concinnus Zone assemblage is identified in the Gauja and Amata of the Baltic, middle and upper Polotsk + Lan' of Belarus, Pashija and Kyn or their analogues of the Central Devonian Field and Timan-Pechora.