Geologicheskii Vestnik

A new fish assemblage occurs in the Tournaisian deposits of the Malaya Usa River Basin, Polar Urals. The assemblage includes acanthodoian cf. Acanthodes sp.; chondrithyans such as phoebodontiforms Thrinacodus bicuspidatus and Thrinacodus ferox, symmoriiforms Denaea cf. fournieri and Symmoriiformes ind., ctenacanthiform Tamiobatis sp., squatinactiform Squatinactis sp., euselachian Sphenacanthus sp.; and actinopterygians. All taxa have been found in the Polar Urals at first time. A most of species are known in the Tournaisian of other regions but Sphenacanthus is discovered in the Tournaisian at first time in the world.

All Tournaisian findings of articulated Acanthodes come from the non-marine deposits and are coincided with different paleocontinents. These oldest representatives of Acanthodes genus, specifically A. lopatini, probably were euryhaline fishes. The presence of such remains in the marine Tournaisian deposits of the Polar Urals indirectly confirms this assumption.

fishes, lower Carboniferous, Polar Urals

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