The Early Carboniferous chondrichthyans of the South Urals, Russia

Vertebrate remains including chondrichthyans were found in the Devonian/Early Carboniferous carbonate beds on the western and eastern slopes of the South Urals. Some of the Late Devonian forms (species of Phoebodus, acanthodians (Devononchus), placoderms and onychodontid sarcopterygians) disappear by the middle Siphonodella praesulcata conodont Zone. The ichthyoassemblages are considerably replenished by the new chondrichthyan taxa in the Polygnathus communis carina and Gnathodus texanus-Mestognathus beckmanni conodont Zones. The chondrichthyans were abundant among the vertebrate faunas of deep-water facies. A new species of chondrichthyan Protacrodus aequalis from the Late Famennian-early Tournaisian of the south Urals is described.