PHAENOCALPIDIDAE Haeckel, 1887

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 : 504-505

Family PHAENOCALPIDIDAE Haeckel, 1887

sensu Caulet emend. herein

Phaenocalpida Haeckel, 1887: 1133, 1157-1158 [as a family]. — Bütschli 1889: 1984 [as a family]. — nec Rüst 1892: 179 [as a family].

?Archiperida Haeckel, 1882: 429 [as a tribe]; 1887: 1133, 1134, 1146 [as a subfamily]. — Wisniowski 1889: 686 [as a subfamily].

Phaenocalpididae – Poche 1913: 220.

Phaenocalpidae [sic] – Popofsky 1913: 331 (= Phaenocalpididae ). — Schröder 1914: 91. — Clark & Campbell 1942: 64; 1945: 34. —

Campbell & Clark 1944a: 39; 1944b: 21. — Dogiel & Reshetnyak 1955: 47. — Chediya 1959: 192. — Tan & Chen 1999: 291. — Tan & Su 2003: 113, 120. — Chen et al. 2017: 178.

?Archiperinae – Campbell 1954: D118. — Chediya 1959: 190.

Clathromitrinae Petrushevskaya, 1971a: 69-71; 1981: 63. — Funakawa 1995b: 211. — Afanasieva et al. 2005: S291-292. — Afanasieva & Amon 2006: 138.

Clathromitridae – Petrushevskaya 1981: 62-63.

TYPE GENUS. — Phaenocalpis Haeckel, 1887: 1173 [type species by subsequent designation ( Campbell 1954: D120): Phaenocalpis petalospyris Haeckel, 1887: 1173 ].

INCLUDED GENERA. —? Archipera Haeckel, 1887: 1155 . — Archiscenium Haeckel, 1882: 429 (= Euscenium n. syn.; Euscenarium n. syn., Plectoscenium; n. syn.). — Clathromitra Haeckel, 1882: 431 . — Conicavus Takahashi, 1991: 117 . — Genetrix Sugiyama, 1994: 5. — Periplecta Haeckel, 1882: 424 . — Phaenocalpis Haeckel, 1887: 1173 . — Pteroscenium Haeckel, 1882: 429 (= Verticillata synonymized by Nishimura 1990: 114). — Spongomelissa Haeckel, 1887: 1209 . — Tripophaenoscenium Campbell & Clark, 1944a: 38 .

NOMINA DUBIA. — Cladoscenium, Dictyocircus , Euscenidium , Phaenoscenium .

DIAGNOSIS. — The Phaenocalpididae consist of a pyramidal one-segmented shell with a single, long apical horn and three long, robust feet. The cephalis is latticed with several arches emerging from the cephalic initial spicular system or is exclusively made of these arches. Each double AL-arch forms a regular suture or a deep-depression suture on the cephalis. Another vertical suture is visible from the apical horn side view that corresponds to the AD-arch. In some members, (e.g., Tripophaenoscenium ), double Al- and AD-arches extend outside the cephalic wall. The A-rod directly arises from the MB to form a straight, free, apical spine on the cephalis. The V-rod forms a significant ventral spine outside the cephalis or may extend horizontally or downwardly. In the latter cases, the extended V-rod forms a short foot or another external spine. Certain members develop more arches. The basal ring directly connects to the D- and double L-rods. These three rods are oriented downward placing the basal ring below the MB. A skirt-like thorax with or without several feet develop in some members, but these feet are generally disconnected from the basal ring. The endoplasm is transparent and located in a space surrounded by the double AL-arch and the basal ring. No algal symbionts have yet been observed in the examined specimens.

STRATIGRAPHIC OCCURRENCE. — Middle Paleocene-Living.

REMARKS

This family name substitutes the commonly used family name “Clathromitridae”. The genus composition of the Phaenocalpididae differs drastically between references. The family characters mainly refer to Clathromitra and not Phaenocalpis due to limited availability of information for the latter genus. Petrushevskaya (1971a: 69-70) established a new subfamily “Clathromitrinae” with members of Archiscenium , Clathromitra , Pteroscenium (= Verticillata in original) and Tripophaenoscenium . Later, Petrushevskaya (1981: 63-72) further added several valid Mesozoic genera (not shown here) and genera such as Corythomelissa, Euscenium , Tripodiscium (originally Tripodisculus and Tripodiscinus ), Phaenocalpis and Spongomelissa . De Wever et al. (2001: 236-238) included “ Clathromitra joergenseni ” among the figures included for the family Sethoperidae ( De Wever et al. 2001: figs 151.1, 151.6); however, the genus name was not included in list of genera included in Sethoperidae . In addition, all the genera assigned by Petrushevskaya (1971a, 1981), except Pteroscenium , were excluded from the list of genera by De Wever et al. (2001). This could mean that Clathromitra was not a member of the Sethoperidae sensu De Wever et al. (2001) and, thus, the “Clathromitridae” sensu Petrushevskaya (1981) was eliminated from the list of De Wever et al. (2001). Petrushevskaya (1971a, 1981) documented the characteristics of the Phaenocalpididae in detail but did not indicate arches on the figures, thereby not confirming them. The cephalic initial spicular system was shown for Clathromitra ( Sashida & Kurihara 1999: fig. 11.14), the Euscenarium -form of Archiscenium ( Nishimura & Yamauchi 1984: pl. 24, fig. 6; Nishimura 1990: figs 23.3-23.5; Takahashi 1991: pl. 24, figs 1-4; Sugiyama & Furutani 1992: pl. 18, fig. 1; Sugiyama et al. 1992; pl. 15, figs 6, 7; Funakawa 1994: fig. 15.1, 15.2; Sugiyama 1994: pl. 2, figs 4, 5, 7, 8), Genetrix ( Sugiyama 1994: pl. 3, figs 1-3), Tripophaenoscenium ( Funakawa 1994: fig. 15.3), Periplecta ( Nishimura & Yamauchi 1984: pl. 24, fig. 3), and the Verticillata -form of Pteroscenium ( Nishimura & Yamauchi 1984: pl. 29, figs 1-8; Nishimura 1990: figs 24.3-24.5). Referring to these photos, some explanations of Petrushevskaya (1981) need to be changed in order to convey an accurate interpretation. The protoplasm was seen in Archiscenium ( Zhang et al. 2018: 19, fig. 7.17), Clathromitra ( Sashida & Kurihara 1999: fig. 11.14) and in the Verticillata -form of Pteroscenium ( Zhang et al. 2018: 18, figs 7.5?, 7.17). Considering these cephalic structures, Conicavus may belong to the Ceratocyrtidae . However, no detailed information regarding this issue has been provided.

Except for critical cases, the Phaenocalpididae can be distinguished from the Sethoperidae by the presence of sutures on the cephalis, a ventral rod extending from the cephalis, the absence of a wired screen on cephalis and thorax, and by not having three wing extensions. Euscenarium , Periplecta and Pteroscenium are sometimes misidentified as a member of the Sethoperidae . They can be differentiated from the member of the Sethoperidae by the presence of a double AL-arch and the absence of straight a -spinules on the A-rod as well as the presence of secondary arches along A- and double L-rods.

VALIDITY OF GENERA

Archiscenium

The initial spicular system is the same among Archiscenium , Euscenium , and Euscenarium . Their differences include the form of the arches connecting the initial spicules, which can resemble A-, double L-, or D-rods, with sizes varying among genera. The exact synonymy requires further study. Archiscenium is the oldest available name among these genera.