PLAGIACANTHIDAE Hertwig, 1879

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: 505-507

publication ID

http://doi.org/ 10.5252/geodiversitas2021v43a15

publication LSID

lsid:zoobank.org:pub:urn:lsid:zoobank.org:pub:DC259A19-9B35-4B33-AD9F-44F4E1DA9983

DOI

http://doi.org/10.5281/zenodo.5106781

persistent identifier

http://treatment.plazi.org/id/038DDA73-FFF2-FE5D-06BA-F888FB4E4D7D

treatment provided by

Felipe

scientific name

PLAGIACANTHIDAE Hertwig, 1879
status

 

Family PLAGIACANTHIDAE Hertwig, 1879 

sensu Dumitrica (2004)

Plagiacanthiden [sic] Hertwig, 1879: 200-202 (= Plagiacanthidae   ) [as a family].

Triplagida Haeckel, 1882: 423 [as a tribe];1887: 908 [as a subfamily].

Plagonida Haeckel, 1882: 423 [nomen dubium, as a subfamily]; 1887: 906-908 [as a family]. — Bütschli 1889: 1975 [as a family]. — Anderson 1983: 29 [as a family].

Tetraplagida Haeckel, 1882: 423 [nomen dubium, as a tribe]:1887: 908, 911 [as a subfamily].

Plectanida Haeckel, 1882: 424 [as a subfamily];1887: 906, 919-921 [as a family]. — Anderson 1983: 29 [as a family].

Polyplagida Haeckel, 1882: 424 [nomen dubium, as a tribe]; 1887: 908, 917 [as a subfamily].

Polyplectida Haeckel, 1882: 424 [as a tribe]; 1887: 921, 929 [as a subfamily].

Tetraplectida Haeckel, 1882: 424 [nomen dubium, as a tribe];1887: 921, 923 [as a subfamily].

Triplectida Haeckel, 1882: 424 [nomen dubium, as a tribe]; 1887: 921 [as a subfamily].

Cystidina [sic] – Haeckel 1884: 30 (= Cystidiidae) [as a family].

Nassellida Haeckel, 1887: 896 [nomen dubium, as a family]. — Anderson 1983: 29 [as a family].

Hexaplagida Haeckel, 1887: 908, 915 [nomen dubium, as a subfamily].

Hexaplectida Haeckel, 1887: 921, 927 [nomen dubium, as a subfamily].

Nasselida [sic] – Bütschli 1889: 1975 (= Nassellidae   ) [as a family].

Plectanidae   – Popofsky 1908: 262; 1913: 277. — Schröder 1914: 72. — Wailes 1937: 12. — Chediya 1959: 166. — Tan & Tchang 1976: 269. — Tan & Chen 1999: 268. — Tan & Su 2003: 81.

Plagoniidae   – Poche 1913: 219 [nomen dubium]. — Campbell 1954: D103. — Riedel 1967b: 295 ( sensu emend.   ); 1971: 655- 656. — Sanfilippo & Riedel 1973: 529. — Nakaseko et al. 1975: 173. — Nakaseko & Sugano 1976: 129. — Riedel & Sanfilippo 1977: 869-870. — Petrushevskaya 1981: 97. — Anderson 1983: 40. — Boltovskoy 1998: 33. — Anderson et al. 2002: 1005. — Afanasieva et al. 2005: S293. — Afanasieva & Amon 2006: 140.

Plagonidae   [sic] – Popofsky 1908: 262 [nomen dubium] (= Plagoniidae   ). — Schröder 1914: 72. — Chediya 1959: 164. — Cachon & Cachon 1985: 291 ( sensu emend.   ).

Nassellidae   – Poche 1913: 219 [nomen dubium]. — Chediya 1959: 163.

Plagoniinae   – Campbell 1954: D103 [nomen dubium].

Cystidiidae – Campbell 1954: D103. — Petrushevskaya 1981: 98. — Afanasieva et al. 2005: S293. — Afanasieva & Amon 2006: 140.

Triplagiinae – Campbell 1954: D104.

Plectaniidae – Campbell 1954: D104. — Chen & Tan 1996: 152. — Chen et al. 2017: 164.

Plectaniinae – Campbell 1954: D104. — Petrushevskaya 1981: 72. — Afanasieva et al. 2005: S292. — Afanasieva & Amon 2006: 139.

Tetraplagiinae – Campbell 1954: D104 [nomen dubium].

Tetraplectinae – Campbell 1954: D104 [nomen dubium]. — Chediya 1959: 166. — Petrushevskaya 1981: 304-305. — Afanasieva et al. 2005: S293. — Afanasieva & Amon 2006: 140.

Triplectinae – Campbell 1954: D104 [nomen dubium]. — Chediya 1959: 166. — Tan & Tchang 1976: 269.

Enneaplegmatinae Campbell, 1954: D105.

Triplaginae – Chediya 1959: 164.

Hexaplaginae – Chediya 1959: 165 [nomen dubium].

Polyplaginae [sic] – Chediya 1959: 165 [nomen dubium] (= Polyplagiidae).

Polyplectinae – Chediya 1959: 167.

Hexaplectinae – Chediya 1959: 167 [nomen dubium].

Plagiacanthidae   – Petrushevskaya 1971a: 69 ( sensu emend.   );1971b: 988-989 ( sensu emend.   ); 1981: 73-74; 1986: 132. — Dumitrica 1979: 28, 30; 2004: 198-199 ( sensu emend.   ). — Goll 1979: 383 ( sensu emend.   ). — Takahashi 1991: 92. — Hollis 1997: 55. — Sugiyama 1998: 233. — Kozlova 1999: 104. — De Wever et al. 2001: 219. — Afanasieva et al. 2005: S268 ( sensu emend.   ). — Afanasieva & Amon 2006: 100.

Plagiacanthinae   – Petrushevskaya 1971a: 147-149; 1971b: 990; 1981: 91-92. — Takahashi 1991: 92. — De Wever et al. 2001: 219, 221. — Dumitrica 2004: 216. — Afanasieva et al. 2005: S269. — Afanasieva & Amon 2006: 102.

Plagiacanthida [sic] – Nishimura 1990: 81 (= Plagiacanthidae   ) ( sensu emend.   ).

TYPE GENUS. — Plagiacantha Claparède   in Müller, 1856: 500 [type species by monotypy: Acanthometra arachnoides Claparède, 1855: 675   ].

INCLUDED GENERA. — Arachnocalpis Haeckel, 1882: 427   . — Cystidium Hertwig, 1879: 214 (= Paracystidium   n. syn.). — Dumetum Popofsky, 1908: 264   (= Pentaplagia   synonymized by Dumitrica 2004: 216). — Enneaplegma Haeckel, 1882: 424   (= Polyplecta   with the same type species). — Jeanpierria Dumitrica, 2004: 217   . — Neosemantis Popofsky, 1913: 298   (= Deflandrella   synonymized by Dumitrica 1978: 240). — Plagiacantha Claparède   in Müller, 1856: 500 (= Plagoniscus   n. syn.; Triplagia   synonymized by Dumitrica 2004: 199; Triplagiacantha synonymized by Petrushevskaya 1981: 96). — Plectagonidium Cachon & Cachon, 1969: 236   . — Plectanium Haeckel, 1882: 424   (= Plectaniscus   n. syn.). — Pseudocubus Haeckel, 1887: 1010   (=? Drepotadium n. syn.; Rhizoplecta   synonymized by Dumitrica 1973a: 836; Talariscus synonymized by Petrushevskaya 1971a: 149).

INVALID NAME. — Hexaplecta.

NOMINA DUBIA. — Hexaplagia   , Hexaplegma   , Nassella   , Plagonidium   , Plagonium, Plectophorina   , Polyplagia   , Tetraplagia   , Tetraplecta   , Triplecta   .

JUNIOR HOMONYMS. — Campylacantha   JØrgensen, 1905 (= Neosemantis   ) nec Scudder, 1897; Obeliscus Popofsky, 1913   (= Talariscus) nec Beck, 1837; Plectophora Haeckel, 1882: 424   (= Plectophorina) nec Gray 1834: captions for pl. 42, fig. 2.

DIAGNOSIS. — The skeleton is exclusively made of bladed, initial spicules. No arch develops between A- and V-rods (e.g., AV-arch) Sagittal ring is absent, unlike other genera of Acanthodesmioidea   . Protoplasm was observed in Cystidium, Neosemantis, Plagiacantha   and Pseudocubus   . The yellowish to brown endoplasm is located within the spicules’ area. In fully grown specimens, the endoplasm extends beyond this area. Except for Cystidium, no algal symbionts are observed in any known genera. Fine pseudopodia radiate around the endoplasm in Cystidium and Neosemantis   . The terminal cone is visible from the base of the Pseudocubus’ cephalic part. No axial projection is observed.

STRATIGRAPHIC OCCURRENCE. — late Middle Eocene-Living.

REMARKS

This taxon is rarely illustrated in references. However, the spicular system of the following genera is examinable in references:? Dumetum   ( Sugiyama 1992a: pl. 1, fig. 5), Neosemantis   ( Nishimura & Yamauchi 1984: pl. 22, figs 7, 10; Nishimura 1990: fig. 13.1, 13.2, 12.4, 12.6; Takahashi 1991: pl. 27, fig. 12; Sugiyama et al. 1992: pl. 20, fig. 2), Plagiacantha   ( Nishimura 1990: fig. 13.3?), and Pseudocubus   (Sugiyama et al. 1992: pl. 18, figs 1-3; Sugiyama 1993: figs 7.1-7.3, 8.1; Funakawa 1995a: pl. 4, figs 1-3, pl. 5, figs 1-3). The shell is too small and too transparent to observe in seawater, as such Plagiacanthidae   can only be identified at higher magnifications (40x or 60x objective lens) with a phase-contrast microscope or a Nomarski differential interference contrast microscope. Under such constraints, “living images” were illustrated for Cystidium ( Anderson 1977: pl. 1, figs 1, 2; Probert et al. 2014: S1, SES 28), Neosemantis   (Matsuoka 2017: fig. 17), Plagiacantha   ( Sashida & Kurihara 1999: fig. 11.18; Suzuki   et al. 2009b: figs 3A, 3B; Zhang et al. 2018: 13, fig. 25), and Pseudocubus   ( Sashida & Uematsu 1994: figs 3.8, 3.9; Sashida & Kurihara 1999: fig. 12.12; Matsuoka 2007: fig. 4d; Suzuki   & Not 2015: fig. 8.11.11; Zhang et al. 2018: 15, fig. 19). Algal symbionts of Cystidium were identified as Brandtodinium nutricula   by Probert et al. (2014). Ultrafine cellular structure was documented for Cystidium ( Anderson 1977).

VALIDITY OF GENERA

Cystidium

The original French description for Paracystidium   is translated as follows: “ Paracystidium   has all the characteristics of Cystidium, except for the occurrence of a very small spicule, free in the protoplasm surrounding the central capsule and located at its aboral pole. ” Cystidium is a type of naked Nassellaria   ; the differences specified in its description are minor and could indicate either different ontogenetic stages or different species. The name Cystidium is older than Paracystidium   .

Plagiacantha  

According to the type-illustrations, Plagiacantha   ( Claparède & Lachmann 1858: pl. 22, fig.9), Triplagia   ( Haeckel 1887: pl. 91, fig.2), and Triplagiacantha ( Hertwig 1879: pl. 7, fig. 6) appear to have only three robust rods, but as the supporting image for Plagiacantha   ( Dumitrica 1973b: pl. 22, figs 2, 4) shows, the main rods are identified as A-, D-, and double L-rods; thus, these genera have four rods in principle. It is likely that a short D-rod was overlooked in these type-illustrations. Triplagia   and Triplagiacantha have been synonymized with Plagiacantha   in previous studies. The architecture of Plagoniscus   is identical to that of Plagiacantha   , except for a long D-rod that has variable length among species. Plagiacantha   is the oldest available name among these genera.

Plectanium  

Plectanium   has six radial spines that arise in two opposite groups from poles of the common central rod ( Campbell 1954: D104). Plectaniscus   has four radial spines that arise from the common central point, and its apical spine differs from three basal spines ( Campbell 1954: D104-105). Specimens identifiable as Plectanium   (the supporting image for Plectanium   in the Atlas   ) possess four bladed rods, not six. It is unnecessary to differentiate these groups at the genus level. If the type-illustration ( Haeckel 1887: pl. 91, fig. 11) is accurate, then the two opposite groups arising from poles of the common central rod illustrated in Haeckel (1887) appear similar to the initial spicular system of the conjoined individuals shown in Dumitrica (2013b: fig. 2.2). The name Plectanium   is older than Plectaniscus   .

Loc

PLAGIACANTHIDAE Hertwig, 1879

Suzuki, Noritoshi, Caulet, Jean-Pierre & Dumitrica, Paulian 2021
2021
Loc

Jeanpierria

Dumitrica 2004: 217
2004
Loc

Paracystidium

Cachon & Cachon 1969
1969
Loc

Pentaplagia

Cachon & Cachon 1969
1969
Loc

Plectagonidium

Cachon & Cachon 1969: 236
1969
Loc

Neosemantis

Popofsky 1913: 298
1913
Loc

Neosemantis

Popofsky 1913
1913
Loc

Obeliscus

Popofsky 1913
1913
Loc

Dumetum

Popofsky 1908: 264
1908
Loc

Plagoniscus

Haeckel 1887
1887
Loc

Plectaniscus

Haeckel 1887
1887
Loc

Polyplagia

Haeckel 1887
1887
Loc

Arachnocalpis

Haeckel 1882: 427
1882
Loc

Enneaplegma

Haeckel 1882: 424
1882
Loc

Plectanium

Haeckel 1882: 424
1882
Loc

Plectophora

Haeckel 1882: 424
1882
Loc

Plagoniidae

Haeckel 1881
1881
Loc

Plagoniidae

Haeckel 1881
1881
Loc

Plagiacanthidae

Hertwig 1879
1879
Loc

Plagiacanthidae

Hertwig 1879
1879
Loc

Plagiacanthinae

Hertwig 1879
1879
Loc

Plagiacanthidae

Hertwig 1879
1879
Loc

Plagiacantha Claparède

Claparede 1858
1858
Loc

Pseudocubus

Haeckel, 1887: 1010: 1010
1010