Frenopyxis, Bobrov & Mazei, 2020

Bobrov, Anatoly & Mazei, Yuri, 2020, Frenopyxis stierlitzi gen. nov., sp. nov. - new testate amoeba (Amoebozoa Arcellinida) from the urban parks with notes on the systematics of the family Centropyxidae Jung, 1942, Zootaxa 4885 (3), pp. 384-394 : 385

Frenopyxis gen. nov.

Description. Shell bilaterally symmetrical, broad elliptic, sometimes almost circular, dorsoventrally flattened, yellowish to colorless; aperture is placed slightly eccentrically on a ventral part of a shell at the bottom of a wide funnel (invagination); aperture usually drop-shaped with narrow side oriented toward closest side; sometimes aperture circular. There is an internal thick organic lip surrounding an aperture and continuing in a bridle, which connects an aperture with the internal side of a shell wall and broaden in the place of connection of a bridle and a shell wall.

Etymology. The name of new taxon reflects its most characteristic feature, i.e. bridle (from Latin— Frenum).

Type species. Frenopyxis stierlitzi sp. nov.

Related genera. New genus differs from the type genus of the family Centropyxis Stein, 1857 by an internal thick organic lip surrounding an aperture and continuing in a bridle, which connects an aperture with the internal side of a shell wall and broaden in the place of connection of a bridle and a shell wall. New genus differs from the genus Armipyxis Dekhtjar, 2009 by luck of internal transversal diaphragms with circular openings, which subdivide internal shell volume into two parts; internal bridle of the new genus connects aperture and shell wall (as in Armipyxis ) but does not subdivide the shell into separate sections.