CRISTALLOSPHAERIDAE Popofsky, 1912

Suzuki, Noritoshi, Caulet, Jean-Pierre & Dumitrica, Paulian, 2021, A new integrated morpho- and molecular systematic classification of Cenozoic radiolarians (Class Polycystinea) - suprageneric taxonomy and logical nomenclatorial acts, Geodiversitas 43 (15), pp. 405-573 : 446-447

Family CRISTALLOSPHAERIDAE Popofsky, 1912

Cristallosphaeridae Popofsky, 1912: 155 — Campbell 1954: D44 [in Collodaria ] — Chediya 1959: 67 [in Collodaria ].

TYPE GENUS. — Cristallosphaera Popofsky, 1912: 155 [type species by monotypy: Cristallosphaera cristalloides Popofsky, 1912: 155] = junior subjective synonym of Calcaromma Thomson, 1877: 99 [type species by monotypy: Calcaromma calcarea Thomson, 1877 : fig. 51 and its associated explanation].

INCLUDED GENERA. — Calcaromma Thomson, 1877: fig. 51 and its associated explanation (page number is variable in editions of the book) (= Cristallosphaera n. syn.). — Enalomelon Sugiyama, 1992b: 195.

DIAGNOSIS. — The protoplasm or outermost shell (if existent) is spherical. Very small, convex lens-shaped spongodiscid siliceous skeleton lies in in the center of the endoplasm or is located somewhere within a large spongy siliceous meshwork. Algal symbionts are found surrounding the endoplasm. In Calcaromma, several starlike materials characterized by an optical anisotropy are scattered in the extracapsular zone of the ectoplasm. These star-like materials are dissolved by acid.

REMARKS

Calcaromma is believed to lack siliceous skeletons and was subsequently considered as belonging to Collodaria ( Haeckel 1862; Popofsky 1913; Campbell 1954; Chediya 1959). Hollande & Enjumet (1960) carefully examined cytological and skeletal characters of Calcaromma (originally Cristallosphaera), and discovered a very small, encrypted, convex lens-shaped spongodiscid siliceous skeleton with a cytological structure similar to that of the flat-shaped spongy skeleton of spumellarians ( Hollande & Enjumet 1960: pl. 15, fig. 10). They concluded that this genus belongs to the classical Spongodiscidae . The presence of the siliceous convex lens-shaped skeleton and the taxonomic position was confirmed by molecular phylogenetic analysis ( Sandin et al. 2021). According to Sugiyama (1992b), Enalomelon is a member of some flat-shaped spongy spumellarian family due to the presence of a very small convex lens-shaped spongodiscid siliceous skeleton within the outermost spherical shell as well as the development of a spongy meshwork. The internal skeletal structure of Enalomelon is illustrated ( Chen 1974: pl. 1, figs 3-6; 1975: pl. 10, figs 1-3; Sugiyama 1992b: pl. 11, figs 1-5). Images of living specimens ( Suzuki & Not 2015: fig. 8.8.7; Matsuoka et al. 2017: appendix A), of the fine cytological structure ( Hollande & Enjumet 1960: pl. 15, fig. 10; pl. 35, figs 1-3) and of algal symbionts ( Zhang et al. 2018: 11, fig. 2) were published for Calcaromma.

VALIDITY OF GENERA

The type specimen of Cristallosphaera is a shrinking Calcaromma specimen in the fixative medium. Calcaromma is an older available name than Cristallosphaera.