Janischewskinidae Reitlinger

Family JANISCHEWSKINIDAE Reitlinger in Rauzer-Chernousova et al., 1996 Test free, nautiloid to compressed laterally, with a juvenarium endothyroid passing to a planispiral final coiling. Coiling follows a progressive increase of the spire with a common rapid increase of the final whorl, in species trending to the uncoiling. Secondary deposits absent. The most common septa are simple, curved backward, but also furrowed, blunt, swollen, and bifurcated. Cribrate aperture in the final whorl, rarely present in the penultimate chambers. Wall microgranular to granular with some agglutinated grains in the more ancestral forms, or with a porous tectum. Late Viseanearly Bashkirian. Remark: The composition of the family Janischewskinidae Reitlinger in Rauzer-Chernousova et al., 1996 has been reviewed by Vachard & Cózar in Liu et al. (2023). The genera Rhodesinella and Groessensella have been considered to be synonyms of Cribrospira and Bibradya, respectively. Composition: Janischewskina Mikhailov, 1939; Bibradya Strank, 1983; Cribrospira Möller, 1878; Parajanischewskina Cózar & Somerville, 2006.