HISTIASTRIDAE Dumitrica, 1989

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 : 449-450

Family HISTIASTRIDAE Dumitrica, 1989 n. stat.

Histiastrinae Dumitrica, 1989: 238 , 241. — De Wever et al. 2001: 157. — Afanasieva et al. 2005: S287. — Afanasieva & Amon 2006: 130.

? Prunobrachidae [sic] Pessagno, 1975: 1014 (= Prunobrachiidae ). — Vishnevskaya 2011: 372; 2015: 12.

TYPE GENUS. — Histiastrum Ehrenberg, 1846: 385 [type species by subsequent designation ( Haeckel 1887: 544): Histiastrum quaternarium Ehrenberg, 1874: 237 ].

INCLUDED GENERA. — Amphicraspedula Haeckel, 1887: 523 (= Amphicarydiscus n. syn., Prunobrachium n. syn.). — Histiastrum Ehrenberg,

1846: 385 (= Histiastromma with the same type species). — Ommathymenium Haeckel, 1887: 520 . — Stephanastrum Ehrenberg, 1846: 385 (= Stephanastromma with the same type species; Hagiastrella n. syn.; Stauralastromma synonymized by Petrushevskaya & Kozlova 1972: 527; Stephanastrella synonymized by Kozur & Mostler 1978: 136).

NOMINA DUBIA. — Stauralastrella , Stauralastrum .

DIAGNOSIS. — This family is characterized by a spongy shell or chambered cylindrical shell, or in certain cases, a flat shell with two or four arms originating from a phorticiid-type medullary shell.

STRATIGRAPHIC OCCURRENCE. — Late Campanian-Living.

REMARKS

Herein, this group is raised from the subfamily Histiastrinae (originally included in family Larnacillidae ) to the family level in order to maintain rank consistency. Internal skeletal structure for both Histiastrum ( Dumitrica 1989: pl. 10, fig. 9) and Ommathymenium ( Dumitrica 1989: pl. 10, figs.10-15) was documented. The morphological variation of the Prunobrachium -form of Amphicraspedula was repeatedly examined ( Zagorodnyuk 1975: 50; Blueford & Amon 1993: pl. 1, figs 8-10; pl. 2, figs 1-9; pl. 3, figs 1-5, 7; Suzuki et al. 2009d: pl. 5, figs 11-16, 18; pl. 6, figs 1-8; Vishnevskaya 2015: pl. 2), but no clear solution was proposed for Ommatogramma, Amphicarydiscus - and Prunobrachium (Sponguridae) due to their strong similarity in external shape ( Zaynutdinov 1978: pl. 1, fig. 5, 6; pl. 2, figs 2, 6; Vishnevskaya 2011: figs 1a-1d). The genus Ommathymenium has generally been misidentified with Ommatogramma (Sponguridae) but the internal structure is evidently quite different (see supporting image for Ommathymenium ).

VALIDITY OF GENERA

Amphicraspedula

Specimens identifiable as the type species of Amphicraspedula (the supporting image of Amphicraspedula in the Atlas ) have the identical internal structure of the type species of Amphicarydiscus ( Lipman 1972: pl. 10, figs 1, 2) and Prunobrachium ( Kozlova & Gorbovetz 1966: pl. 1, figs 5, 6). Differing from Amphicraspedula , the type species of Amphicarydiscus lacks robust radial spines whereas the type species of Prunobrachium shows a cylindrical appearance. These differences are, however, interpreted as intraspecies variations. The oldest available name is Amphicraspedula among them.

Stephanastrum

Stephanastrum has the same type species as Stephanastromma . Stauralastromma is characterized by spiny arms and no patagium ( Campbell 1954: D88), but these differences are related to intraspecies and intraspecies variations or preservation effect. Hagiastrella is defined by similar longitudinal arms with patagium ( Campbell 1954: D86), the length symmetry of the arms is different among species but not genera. Stephanastrum is characterized by a patagium with four large interbrachial openings (patagial girdle) ( Campbell 1954: D88), but a difference in the patagium is not considered as a generic difference.