CERATOCYRTIDAE Petrushevskaya, 1981

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 : 501

Family CERATOCYRTIDAE Petrushevskaya, 1981 n. stat.

sensu Caulet emend. herein

Ceratocyrtinae Petrushevskaya, 1981: 108-109. — Afanasieva et al. 2005: S295. — Afanasieva & Amon 2006: 143-144.

TYPE GENUS. — Ceratocyrtis Bütschli, 1882: 536 [type species by subsequent designation ( Petrushevskaya 1971a: 98): Cornutella ? cucullaris Ehrenberg, 1874: 221].

INCLUDED GENERA. — Ceratocyrtis Bütschli, 1882: 536 (= Bathrocalpis synonymized by Petrushevskaya 1971a: 98; Helotholus synonymized by Petrushevskaya 1975: 587). — Entepipedus Sugiyama, 1994: 6. — Gomisterna Sugiyama, 1994: 8. — Gondwanaria Petrushevskaya, 1975: 584 . — Lipmanella Loeblich & Tappan, 1961: 226 . —? Periarachnium Haeckel, 1882: 430 . —? Phlebarachnium Haeckel, 1882: 430 .

JUNIOR HOMONYM. — Dictyoceras Haeckel, 1862 (= Lipmanella ) nec Eichwald, 1860.

DIAGNOSIS. — Ceratocyrtidae are described as Plagiacanthoidea with a very small cephalis and a large thorax or relevant shell. Apical horn and wings may be present or absent. No feet are observed. The collar stricture is located above the MB’s level. The MB generally rises to the apical side with the double L-rod that extends horizontally. The double l-rod is present in most members. The double AL-arch forms part of the collar stricture or appears as a horizontal line near the bottom of the cephalic wall. The architecture of the cephalic initial spicular system is variable within the family: a crowned ring above MB, made of double VL- and AL-arches is present in Ceratocyrtis, Gomisterna and Gondwanaria ; while a basal ring, made of double LV- and Ll-arches, is found free from the shell wall in Lipmanella . The transparent to colored endoplasm forms long lobes below the cephalis. A gelatinous matter covers the shell in Phlebarachnium . No algal symbionts are found in Ceratocyrtis and Lipmanella , while plenty of algal symbionts surround the shell of Phlebarachnium .

STRATIGRAPHIC OCCURRENCE. — Late Paleocene-Living.

REMARKS

All the genera, except for Ceratocyrtis , were not treated in De Wever et al. (2001). Petrushevskaya (1981) established the subfamily “Ceratocyrtinae” with the following members Antarctissa, Ceratocyrtis , Gondwanaria , Periarachnium , Phlebarachnium and Pseudodictyophimus . Antarctissa and Pseudodictyophimus were excluded herein based on the different architecture of their cephalic initial spicular system. In contrast, Entepipedus, Gomisterna and Lipmanella with double l-rod or double AL-arch that form a horizontal line in the lower part of the cephalis were included.

The cephalic initial spicular system has been well documented in Ceratocyrtis ( Petrushevskaya 1986: pl. 1, fig. 1; Sugiyama 1993: figs 20.4-20.6, 23.1; Sugiyama & Furutani 1992: pl. 18, fig. 6; pl. 20, fig. 2; Sugiyama et al. 1992: pl. 15, figs 2-3; Funakawa 1994: fig. 7.1; 1995a; pl. 1, figs 4, 5), Entepipedus ( Sugiyama 1994: pl. 4, fig. 4), Gomisterna ( Sugiyama 1994: pl. 5, fig. 1), Gondwanaria ( Nishimura 1990: fig. 17.4-17.6; Sugiyama et al. 1992: pl. 21, fig. 9; Funakawa 2000: pl. 1, figs 1-3; pl. 2, figs 1-3), Lipmanella ( Nishimura & Yamauchi 1984: pl. 35, fig. 3; Sugiyama & Furutani 1992: pl. 17, fig. 1; Funakawa 2000: pls 3-6), and Periarachnium ( Aita et al. 2009: pl. 5, fig. 7c). Entepipedus has a very particular cephalic initial spicular system, thus, its exact taxonomic position is unknown. “Living” or protoplasmic images were reported for Ceratocyrtis ( Sashida & Kurihara 1999: fig. 12.9; Zhang et al. 2018: 15, fig. 3?, 4), Lipmanella ( Matsuoka et al. 2001: pl. 1, fig. 3; Matsuoka 2007: fig. 5c; Sashida & Kurihara 1999: fig. 11.3; Suzuki & Aita 2011: fig. 5O; Suzuki & Not 2015: figs 8.4.2, 8.10.6; Zhang et al. 2018: 15, fig. 15, p. 21, fig. 7, p. 23, fig. 12), and Phlebarachnium ( Aita et al. 2009: pl. 30, figs 5a-5d, p. 32, fig. 4; Zhang et al. 2018: 21, fig. 13).

VALIDITY OF GENUS

Ceratocyrtis

The taxonomic confusion problem between Bathrocalpis, Ceratocyrtis and Helotholus sometimes arises in questions. The discussion in Matsuzaki et al. (2015) was based on the “ lectotype ” of Helotholus histricosus by Dolven et al. (2014). This “ lectotype ” was different from the type-illustration ofJØrgensen (1905) because it lacks a neck at cephalis position.An important Southern Ocean species, “ Helotholus vema ”, does not belong to Helotholus or Ceratocyrtis but is similar to Steganocubus . Sugiyama (1993: 69) had already noticed the necessity of further studies to resolve these taxonomic inconsistencies.