N. D. Sinitshenkova and D. S. Aristov

The biggest fossil mayfly (Insecta: Ephemerida = Ephemeroptera) from the Upper Permian locality of Isady, northern European Russia.

Number: 255, Pages: 8 - 10

From the Upper Permian (Severodvinian Stage, Poldarsa Formation) locality of Isady (Velikoustyugskii District, Vologda Region, European part of Russia) new genus and species of mayfly Ponalex maximus gen. et sp. n. from the family Protereismatidae is described and illustrated based on the unique remain of the hindwing. This new species is the biggest known mayfly.

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