A new species of the fossil pufferfish genus †Archaeotetraodon (Tetraodontidae) from the Middle Miocene of the North Caucasus, Russia.

The fossil puffer fish genus †Archaeotetraodon Tyler & Bannikov, 1994 is unique among the Tetraodontidae in having the upright central spinule of the dermal scale plates bifid rather than singular and undivided. Six species of this genus have previously been described variously from the Oligocene and Miocene of Russia, Italy, Algeria, and Ukraine. Described herein is a seventh species of this genus, †Archaeotetraodon bemisae sp. nov., based upon two specimens from the Pshekha River, Krasnodar Region, North Caucasus, Russia. These Maikopian specimens are no less than 15 mya, in the basal-most Middle Miocene. The new species is distinguished from the other six species in the genus by the following combination of characters: thick, sturdy, and smooth bifid spinules; frontal width broad over the orbit; 18 vertebrae; slender ventral postcleithrum; a moderately long rayless pterygiophore; height/length ratio of the posteriormost abdominal centrum being 0.78-0.79; 10 dorsal-fin rays; 9 anal-fin rays; and 14 pectoral-fin rays.