New Genus of the Actinopterygian Fishes (Eurynotoidiidae) from the Urzhumian of Republic of Tatarstan (Kluchevskoy Ovrag locality)

Abstract

New genus and species of eurynotoidiid actinopterygians (Eurynotoidiformes), Kluchevichthys praeclarus gen. et sp. nov., is described from the uppermost Urzhumian (Kluchevskoy Ovrag locality), Tetushi District, Republic of Tatarstan. The holotype of а new form is an almost complete, non-deformed skeleton. The diagnostic characters of K. praeclarus were obtained in the morphology of the skull roof bones, dental system, scales and fins. The morphology of the marginal dentition, combining the tricuspid pattern of tooth crowns with the conical shape of all their apices allows positioning of a new taxon at the base of most phylogenetic branches of herbivorous Eurynotoidiformes having more specialized condition of the dental system, which corresponds well to stratigraphic data.

Keywords

• actinopterygii
• eurynotoidiidae
• russia
• republic of tatarstan
• middle permian
• urzhumian
• kluchevichthys praeclarus
• phytophagy
• phylogeny