HEXACARYIDAE Haeckel, 1882

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 : 414-415

Family HEXACARYIDAE Haeckel, 1882 n. stat.

Hexacaryida Haeckel, 1882: 454 [as a tribe]; 1887: 170, 202 [as a subfamily]. — Schröder 1909: 9 [as a subfamily].

Haliphormida Haeckel, 1882: 428 [below tribe].

Hexacaryinae – Chediya 1959: 93. TYPE GENUS. — Hexacaryum Haeckel, 1882: 454 (type species by subsequent monotypy: Hexacaryum arborescens Haeckel, 1887: 203 ).

INCLUDED GENERA. — Cleveiplegma Dumitrica, 2013a: 24 . — Haliphormis Ehrenberg, 1846: 385 (= Hexastylanthus n. syn., Hexastylettus n. syn., Hexastylissus synonymized byTakahashi 1991: 71, Hexastylurus n. syn.). — Hexacaryum Haeckel, 1882: 454 . — Hexalonchetta Haeckel, 1887: 182 . — Hexancistra Haeckel, 1879: 705 (= Hexancora with the same type species). — Hexapitys Haeckel, 1882: 451 .

INVALID NAME. — Hexadendron.

NOMINA DUBIA. — Hexadendrum , Hexastylarium , Hexastylidium .

DIAGNOSIS. — Six primary radial spines arise directly from a heteropolar or tetrapetaloid microsphere. They are generally distributed at right angles of each other. One spherical lattice shell, one octahedral shell with a polygonal frame, or a similar-shaped meshwork cover can be observed.

Protoplasm is illustrated for Cleveiplegma , Hexapitys and Haliphormis . The endoplasm is very small and fills the medullary shells and is also distributed around the medullary shell.In certain members, undeterminable transparent and brown granules surround the endoplasm. Algal symbionts are sometimes observed. When observed, algal symbionts are found at least inside the cortical shell (in the case of Haliphormis ).

STRATIGRAPHIC OCCURRENCE. — Late Paleocene-Living.

REMARKS

The available family-rank name “Haliphormida” and “Hexacaryida” were simultaneously published in Haeckel (1882). “Haliphormida” was established below the tribe, while “Hexacaryida” was established at the tribe rank, thus the valid family is “Hexacaryida.” according to the ICZN (1999) Article 24.1. The internal skeletal structure was illustrated for Cleveiplegma ( Dumitrica 2013a: pl. 1, figs 1-9) and Hexalonchetta ( Anderson et al. 1986a: pl. 1, figs 3, 4). Protoplasm and algal symbionts were documented by epi-fluorescent DAPI dyeing methods in Cleveiplegma ( Zhang et al. 2018: 14, fig.1), Hexapitys ( Zhang et al. 2018: 11, fig. 17) and Haliphormis ( Zhang et al. 2018: 11, fig. 18). The fine protoplasmic structure was illustrated in Cleveiplegma ( Hollande & Enjumet 1960: pl. 47, fig. 5). In the catalogue, the Hexacaryidae appear to be incorporated into different families. In poor preservation conditions, taxa with a single spherical cortical shell with six radial spines tend to be misidentified as Hexalonchetta (Hexacaryidae) , Haliphormis (Hexacaryidae) , six radial spine types of Anomalosoma ( Hollandosphaeridae ), six radial spine types of Centrolonche (Centrocubidae) and six radial spine types of Stigmostylus (Centrocubidae) . It is essential to identify their internal structures in order to differentiate them. If the internal structure is lost, they will be related to Haliphormis .

VALIDITY OF GENERA

Hexancistra

As Hexancistra and Hexancora have the same objective type species, the older synonym is selected as the valid name.

Haliphormis

The oldest available name is Haliphormis . Haliphormis corresponds with the widely used concept of “ Hexastylus ” (a Mesozoic genus; see O’Dogherty et al. 2009a). The former was first synonymized with Hexastylanthus , Hexastylettus Hexastylissus , and Hexastylurus . The latter four genera have the following morphological characters: regular pores and smooth surface for Hexastylanthus , regular pores and spiny surface for Hexastylettus ; irregular-shaped pores of different sizes for Hexastylissus ; irregular-shaped pores of dissimilar in shape and spiny surface for Hexastylurus ( Campbell 1954: D58). The lectotype of Haliphormis looks an empty space in the shell ( Suzuki et al. 2009c: pl. 69, figs 1a-d) although the other specimen in the same microscopic slide has three concentric shells ( Suzuki et al. 2009c: pl. 69, figs 2a-c). If these two specimens are conspecific each other, Haliphormis would not belong to the Hexacaryidae and would not be a senior synonym of Hexastylanthus , Hexastylettus , Hexastylissus and Hexastylurus . If we accept the topotypes, one of Hexastylanthus , Hexastylettus , Hexastylissus and Hexastylurus must be validated. This issue will put aside this time because real species without any internal structure are suspect for “ Hexastylus ”.