Cryptomanicula, Dumitrica, 2019

Dumitrica, Paulian, 2019, Cenozoic Spumellarian Radiolaria With Eccentric Microsphere, Acta Palaeontologica Romaniae 15 (1), pp. 39-60 : 48-51

Genus Cryptomanicula nov. gen.

Type species. Cryptomanicula absconsa nov. sp.

Diagnosis. Shell thin, lens-shaped, circular and spongy, without arms. Initial skeleton of Trimanicula type included in the centre of shell, and the three primary rays not prolonged beyond periphery of shell. Inner shell with many secondary and tertiary rays, none of them extended outside periphery of shell.

Etymology. From the Latin crypta – hidden and manicula – small hand. Feminine gender.

Remarks. By its external shape and the spongy shell, this genus resembles a spongodiscid from which it differs in having an initial skeleton of Trimanicula type as described and illustrated by Dumitrică (1991, pl. 3, figs. 4, 5; pl. 8, figs. 2, 3, 9-11). This structure is very well visible in the holotype and sectioned paratype of the type species of Cryptomanicula ( Fig. 5 ). Its origin was probably in the species Trimanicula penultima Dumitrică , although no transitional species was until present discovered. Absence of such species is not surprizing given the extreme scarcity of the genus Trimanicula in the Paleocene.

Range and occurrence. DSDP 21-208-30 CC, early Paleocene, Prinsius martini nannoplankton Zone, so far as known.

Figures

Fig. 5 a-e - Cryptomanicula absconsa nov. gen., nov. sp.; a – holotype, b – same, central part magnified. c-e – paratype with one cortical layer struck off with a razor blade: c – general view from the surface, d – same, viewed from the struck off face, focussed on primary rays; e – same, focussed on the 7-sided initial ring. All scale bars = 50 μm