Mrabella subcarinata comb. nov. Kosakyan, Lahr, Mulot, Meisterfeld, Mitchell and Lara

1957 Quadrulella subcarinata Gautier-Lièvre, Bull. Soc. Hist. Nat. Afr. Nord. t. 48: 500.

Updated description. With characters of the genus. Dimensions (based on three individuals) of the test: L = 201 – 218 µm, B = 105 – 127 µm. Aperture 35 – 37.5 µm wide, curved and bordered by a think organic lip.

Differential diagnosis. M. subcarinata is similar to Gibbocarina galeata in general shape of the test and in the presence of a wide, hollow, tuberous keel. Gibbocarina galeata is generally larger, but sizes overlap: L = 180 – 283 µm, B = 94 – 190 µm in G. galeata versus L = 201 – 218 µm, B = 105 – 127 µm in M. subcarinata . As far as we know, G. galeata never presents a shell composed entirely of rectangular plates, as is the case in M. subcarinata . M. subcarinata may be confused with M. plicata, which has a similar shape and keel, but it is smaller (L = 111 – 135 µm, B = 49 – 62 µm).

Type. Fig. 4 b (Gauthier-Lièvre, 1957); paratype Fig. 7 a (present study).