PARADICTYIDAE 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 : 493-494

Family PARADICTYIDAE Haeckel, 1882 n. stat.

sensu Petrushevskaya (1981)

Paradictyida Haeckel, 1882: 444 [as a tribe].

Nephrospyrida Haeckel, 1887: 1092, 1099 [as a subfamily].

Nephrospyrinae [sic] – Chediya 1959: 185 (= Nephrospyridinae).

Paradictyinae – Campbell 1954: D116. — Petrushevskaya 1981: 369-370. — Afanasieva et al. 2005: S306. — Afanasieva & Amon 2006: 157.

Nephrospyridinae – Petrushevskaya 1981: 352-352. — Afanasieva et al. 2005: S305. — Afanasieva & Amon 2006: 155.

TYPE GENUS. — Paradictyum Haeckel, 1882: 444 [type species by absolute tautonomy: Nephrospyris paradictyum Haeckel, 1887: 1102 ] = junior subjective synonym of Nephrodictyum Haeckel, 1882: 444 [type species by subsequent designation ( Campbell 1954: D106): Nephrospyris renilla Haeckel, 1887: 1101 ].

INCLUDED GENERA. — Amphispyris Haeckel, 1882: 443 (= Amphispyrium with the same type species; Amphispyridium n. syn., Microcubus n. syn., Toxarium n. syn., Toxellium n. syn., Toxidiella n. syn., Toxonium n. syn.,? Tricyclidium n. syn.). — Nephrodictyum Haeckel, 1882: 444 (= Nephrospyris with the same type species; Paradictyum synonymized by Goll & BjØrklund 1985: 115). — Psychospyris Riedel & Sanfilippo, 1971: 1591 . — Sphaerospyris Haeckel, 1887: 1099 .

NOMEN DUBIUM. — Protympanium .

JUNIOR HOMONYM. — Toxidium Haeckel, 1887 (= Toxidiella ) nec Le Conte, 1860.

DIAGNOSIS. — Main skeleton forming a sagittal ring with twin cupolas or twin set of body frames. The Lo-axis is parallel to Sg-axis and the Sh-axis is parallel to the Pl-axis. No significant skeleton developed below the basal ring. The basal ring is constructed of three or six basal pores. Basal pores are partly, or fully, covered with fine polygonal meshes in some members. The endoplasm is spherical and situated in the area inside the sagittal ring. Both cupolas are almost occupied with tens to a hundred number of algal symbionts in Amphispyris . In Nephrodictyum , a hundred algal symbionts are exclusively distributed in the periphery or in the peripheral lobes of the shell. No algal symbionts are located outside the shell.

STRATIGRAPHIC OCCURRENCE. — Late Paleocene-Living.

REMARKS

Nephrodictyum and related genera were hitherto included in the Acanthodesmiidae ( De Wever et al. 2001: 231-232) , but the orientation of the axes under Type 2 to Type 1 coordinates is fundamentally different between the Paradictyidae and the Acanthodesmiidae . Differing from the Paradictyidae , the Acanthodesmiidae have the Lo-axis parallel to the Ltaxis. The protoplasm, living status and cytological ultrafine structure were documented for Amphispyris ( Sugiyama & Anderson 1998b; Suzuki & Not 2015; fig. 8.11.4; Zhang et al. 2018: 10, figs 2.11), Nephrodictyum ( Cachon & Cachon 1985: fig. 53.d; Zhang et al. 2018: 10, fig. 2.18), and the Paradictyum form of Nephrodictyum ( Aita et al. 2009; pl. 5, fig. 1a-2b; pl. 31, fig. 7).

VALIDITY OF GENERA

Amphispyris

Amphispyris is different from Tricolospyris at the family level as written in remarks and diagnosis of the Acanthodesmiidae and Paradictyidae , and this difference is well illustrated in Goll (1968: pl. 176, fig.13;1972b: pls 1-16), Petrushevskaya (1969: figs 4.IV, 4.V) and Tan & Su (1981: pls 1-3). The following genus combinations share the same type species: Amphispyris and Amphispyrium ; Toxarium and Toxellium ; and Toxidium and Toxidiella . In Campbell (1954) and Haeckel (1887) there is a very strong link in the Nassellaria at a suborder level and family-rank. Four genera ( Microcubus , Toxarium , Toxonium , Tricyclidium ) are classified in the “Division Plectellari” ( Campbell 1954: D103) and two genera in the “Division Cyrtellari” ( Campbell 1954: D111). As the “division”was situated between the “ Nassellaria ” and the “superfamily” in Campbell (1954), this rank is now equal to the suborder rank. “Plectellari” is defined by “without complete skeleton” whereas “Cyrtellari” is defined by “complete lattice shell”. The fundamental framework of the genera listed here is the same. Due to this reason, these divisional schemes do not reflect difference in real specimens. The next link in a classic study is the family rank. These genera were then classified into different superfamilies, families and subfamilies but these descriptions were logically wrongly applied: the anatomical orientation and apparent orientation under the absolute Cartesian coordinates for the former and relative Cartesian coordinates for the latter (see remarks of the Acanthodesmioidea ). However, these coordinates were confused in the Paradictyidae (see diagnosis and remarks of the Paradictyidae ). Amphispyris and Amphispyridium were classified into the “Androspyrididae” of the “superfamily Triospyridicae ” by presence of a thorax and cephalis with an apical cupolar at family level ( Campbell 1954: D116) and existence of a bilocular cephalis with a sagittal constriction at the superfamily level ( Campbell 1954: D112). These criteria are meaningless because recognizing cephalis, thorax and apical cupolar can be wrong, owing to a wrong recognition of the absolute orientation of the shell. Thus, the distinguishing criteria for subfamily and any higher levels are not any longer valuable for the Paradictyidae .

Once the link at suborder level and family-rank dissolved, synonym discussion becomes easy. Goll (1972b) identified “ Tholospyris devexa devexa ” and “ Tholospyris devexa finalis ” successively for specimens with incomplete latticed shells ( Goll 1972b: pl. 10 for the former and pl. 12, figs 9-12 for the latter) and complete latticed shells ( Goll 1972b: pl. 11 for the former and pl. 13 for the latter). The incomplete latticed forms can be identified as Toxarium or Toxonium if the type-illustrations of these genera are referred to. The definition of these two genera is based on the number of columellae, basal ring, equatorial ring, and thoracic bows ( Campbell 1954: D108 for Toxarium and D109 for Toxonium ), but it is unable to be reworded by the current terminology. A complete latticed shell can be identified as Amphispyris or Amphispyridium . These two genera have in common a shell with two transvers strictures and a latticed structure only complete in the frontal ring ( Campbell 1954: D116 for both genera). Although the true meaning of the “frontal ring” is unclear, this description fits with real specimens. Amphispyris has three pairs of large annular meshes on each side of the ring-plane whereas Amphispyridium has four pairs instead of three pairs, but this difference cannot be recognized in the type-illustrations of these two genera ( Haeckel 1887: pl. 88, fig. 4 for Amphispyris and pl. 88, fig. 2 for Amphispyridium ). Thus, four genera Toxarium , Toxonium, Amphispyris and Amphispyridium are a same genus.

The specimen identifiable as Tricyclidium based on the genus definition by Campbell (1954: D108) is identified as a specimen of T. devexa devexa in Goll (1976: pl. 10, fig. 1) and that of Microcubus is named as “ Tholospyris devexa dusenburyi ” ( Goll 1976: pl. 12, figs 1-8). These images indicate that Tricyclidium and Microcubus are different as ontogenetic growth stages at the species level. Amphispyris , Microcubus and Tricyclidium were simultaneously published in Haeckel (1882: 443 for Amphispyris , 446 for Microcubus and Tricyclidium ). Real specimens corresponding to Amphispyris were found at many locations so that this genus is selected as a valid genus.