Family CIRCODISCIDAE Dumitrica, 1989 n. stat.

Circodiscinae Dumitrica, 1989: 237-238 . — De Wever et al. 2001: 156. — Afanasieva et al. 2005: S287. — Afanasieva & Amon 2006: 130. — Zhang & Suzuki 2017: 54 .

TYPE GENUS. — Circodiscus Kozlova in Petrushevskaya & Kozlova, 1972: 526 [type species by monotypy: Trematodiscus microporus Stöhr, 1880: 108].

INCLUDED GENERA. — Annulatospira Clark & Campbell, 1945: 26. — Circodiscullus Dumitrica, 2020: 30. — Circodiscus Kozlova in Petrushevskaya & Kozlova, 1972: 526 (= Plectodiscus synonymized by Petrushevskaya 1975: 575). — Sanfiriedelus Dumitrica, 2020: 18. — Stylotrochellus Dumitrica, 2020: 33.

DIAGNOSIS. — Phorticioidea with a discoid shell having as medullary shell the first or first two systems of girdles and the outer shell formed of rings, spirals or more or less spongy meshwork.

STRATIGRAPHIC OCCURRENCE. — Middle Paleocene-Living.

REMARKS

This family is raised herein from the subfamily Circodiscinae (originally included in the family “ Larnacillidae ”) in consideration of rank consistency. Internal skeletal structure is illustrated for Circodiscus (Dumitrica 1989: pl. 9, figs 7-10; pl. 14, figs 7, 8).