PYLOBOTRYDIDAE 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 : 509-513

Family PYLOBOTRYDIDAE Haeckel, 1882

sensu Sugiyama (1998)

Pylobotrida Haeckel, 1882: 440 [as a subfamily].

Cannobotrida Haeckel, 1882: 440 [nomen dubium, as a subfamily].

Pylobotryida – Haeckel 1887: 1107, 1119-1120 ( sensu emend. ) [as a family]. — Bütschli 1889: 1983 [as a family]. — Anderson 1983: 29 [as a family].

Cannobotryida – Haeckel 1887: 1107-1108 [nomen dubium, as a family]. — Bütschli 1889: 1982 [as a family]. — Anderson 1983: 29 [as a family].

Botryocellida Haeckel, 1887: 1112 [as a subfamily].

Botryopylida Haeckel, 1887: 1112 [nomen dubium, as a subfamily].

Botryocampida Haeckel, 1887: 1120 [as a subfamily].

Botryocyrtida Haeckel, 1887: 1120 [as a subfamily].

Cannobotryidae [sic] – Poche 1913: 222 [nomen dubium] (= Cannobotrydidae). — Schröder 1914: 143. — Chediya 1959: 185. — Riedel 1967b: 296 ( sensu emend. );1971: 657-658. — Riedel & Sanfilippo 1970: 536; 1971: 1601. — Petrushevskaya 1971a: 154-159; 1981: 315. — Sanfilippo & Riedel 1973: 532. — Nakaseko et al. 1975: 174. — Nakaseko & Sugano 1976: 131. — Pessagno 1976: 54. — Dumitrica 1979: 35. — Cachon & Cachon 1985: 295. —Sanfilippo et al. 1985: 704. — Yeh 1987: 86 ( sensu emend. ). — Nishimura 1990: 169 ( sensu emend. ). — Takahashi 1991: 133. — Boltovskoy 1998: 33-34. — Sugiyama 1998: 233. — Kozlova 1999: 133. — Tan & Chen 1999: 282. — Anderson et al. 2002: 1018. — De Wever et al. 2001: 243-245. — Tan & Su 2003: 106. — Afanasieva et al. 2005: S303-304. — Afanasieva & Amon 2006: 153. — Chen et al. 2017: 171, 233.

Pylobotryidae [sic] – Poche 1913: 222 (= Pylobotrydidae ). — Schröder 1914: 143. — Chediya 1959: 187.

Acrobotrusidae Popofsky, 1913: 314 [nomen dubium].

Neobotryisidae [sic] – Popofsky 1913: 319-400 (= Neobotrydidae).

Cannobotrydidae – Campbell 1954: D143 [nomen dubium].

Glycobotrydidae Campbell, 1954 : D143. — Tan & Tchang 1976: 272. — Tan & Su 1982: 167; 2003: 108. — Tan & Chen 1999: 283.

Botryocampinae – Campbell 1954: D144. — Chediya 1959: 187.

Pylobotrydidae – Campbell 1954: D144. — Tan & Su 1982: 168; 2003: 111. — Chen & Tan 1996: 153. — Tan & Chen 1999: 286. — Chen et al. 2017: 172.

Pylobotrydinae [sic] – Campbell 1954: D144 (= Pylobotrydinae). — Tan & Su 1982: 168. — Chen et al. 2017: 172.

Botryocellinae – Chediya 1959: 186.

Botryopylinae – Chediya 1959: 186 [nomen dubium].

Botryocyrtinae [sic] – Chediya 1959: 187 (= Botryocyrtidinae).

Cannobotrythidae [sic] – Riedel & Sanfilippo 1977: 879 [nomen dubium] (= Cannobotrydidae).

Botryocyrtididae – Petrushevskaya 1981: 309. — Amon 2000: 61-62. — Afanasieva et al. 2005: S303. — Afanasieva & Amon 2006: 153.

TYPE GENUS. — Pylobotrys Haeckel, 1882: 440 [type species by subsequent designation ( Campbell 1954: D144): Pylobotrys putealis Haeckel, 1887: 1121 ].

INCLUDED GENERA. — Amphimelissa JØrgensen, 1905: 136 (= Bisphaerocephalina synonymized by Petrushevskaya 1971a: 158; Bisphaerocephalus synonymized by Petrushevskaya 1971a: 165;? Glycobotrys n. syn.). — Botryocampe Ehrenberg, 1861b: 829 (= Saccospyris synonymized by Matsuzaki et al. 2015: 59). — Botryocella Haeckel, 1887: 1116 . — Botryocyrtis Ehrenberg, 1861b: 829 (=? Acanthobotrys synonymized by Petrushevskaya & Kozlova 1972: 554). — Centrobotrys Petrushevskaya, 1965: 113 . — Lithocorythium Ehrenberg, 1847: 54 (=? Phormobotrys n. syn.). — Monotubus Popofsky, 1913: 322. — Neobotrys Popofsky, 1913: 320 (= Xiphobotrys n. syn.). — Pylobotrys Haeckel, 1882: 440 (= Acrobotrissa n. syn., Ceratobotrys n. syn.; Acrobotrella synonymized by Petrushevskaya 1981: 319).

NOMINA DUBIA. — Acrobotrantha, Acrobotromma, Acrobotrusa, Acrobotrys , Botryopyle , Cannobotrys, Cannobotrantha, Cannobotrella, Cannobotrissa, Cannobotromma, Cannobotrusa, Diauletes.

JUNIOR HOMONYMS. — Acrobotrissa Popofsky, 1913 (= Acrobotrissa) nec Haeckel, 1887; Lithobotrys Haeckel, 1887 (= Glycobotrys ) nec Ehrenberg, 1844 ( Ehrenberg 1844a).

DIAGNOSIS. — Pylobotrydidae consist of two to three segments and a complex cephalis. The cephalic part is subdivided in ante-, eu-, and postcephalic lobes. The antecephalic lobe appears as an inflated part on the ventral side, between the V- and double L-rods; the eucephalic lobe is observed as an inflated space in the central part between the A- and V-rods, while the postcephalic lobe appears as an inflated space in the apical side, between the A- and D-rods. The eucephalic lobe is noticeably larger than the postcephalic lobe. The cephalic initial spicular system consists of MB, A-, V-, D-, double L-, double l-, and Ax-spines. Double l-rods are well developed and protrude as spines from the shell wall. The basal ring is developed. Double ap -arch (a kind of AL-arch) and double pj -arch (a kind of LV-arch) are both developed. A deep distinctive suture generally develops between the lobes and in some members, a flat divider made of arches is also visible between the postcephalic and eucephalic lobes. A tube located between the eu- and antecephalic lobes, is closely related to the V-rod.

The arrangement of the protoplasm and algal symbionts, as well as the color of the endoplasm, are variable among genera. The ante- and postcephalic lobes are occupied by algal symbionts in Pylobotrys , Amphimelissa and Centrobotrys , whereas the algal symbionts are located on the distal end of the endoplasm in Botryocyrtis and Monotubus.

STRATIGRAPHIC OCCURRENCE. — late Middle Eocene-Living.

REMARKS

The definition of ante-, eu- and post-cephalic lobes is that employed by Sugiyama (1998: fig. 3). This family was originally called Cannobotrydidae. However, owing to the nomen dubium status of the type genus of Cannobotrydidae, it has been replaced with valid family name: Pylobotrydidae . The stem of the genitive singular of Pylobotrys is Pylobotryd-. According to Article 29.3.1, if the stem ends in -id, those letters may be elided before adding the family-group suffixes. Although the grammatic spelling of the family derived from Pylobotrys may be “ Pylobotryidae ”, prevailing usage “ Pylobotrydidae ” ( Tan & Su 2003: 111; Chen et al. 2017: 172) is hereby retained in accordance with Article 29.5 (maintenance of current spelling). Sugiyama (1998: 233) pointed out the morphological similarity of this family with Dimelissidae (= Lophophaenidae in original) due to the small size, the similar development of arches, and the similarity in the cephalic initial spicular system (concerning the presence or absence of the double l-rods). This view was supported by molecular phylogenic studies because Pylobotrys falls into the same clade as the Plagiacanthoidea , Clade G ( Sandin et al. 2019). In fact, Entepipedus ( Ceratocyrtidae ) has an intermediate form which consists of the presence of double l-rods and the absence of cephalic lobes.

A genus belonging to the Pylobotrydidae is identifiable by: 1) the recognition of the A- and V-rods; 2) the relative position between MB and the collar stricture development, defined by the position of the lobes; and 3) the spines and wings derived from the cephalic initial spicular system. A comprehensive examination of the Pylobotrydidae was conducted under light microscopy by Petrushevskaya (1964, 1965, 1968), and was partly confirmed in scanning electron microscopy (SEM) and through other observation methods. SEM images were provided for Pylobotrys ( Nishimura 1990: figs 37.1-37.3), Amphimelissa ( BjØrklund & Swanberg 1987: figs 3, 4), Botryocella ( O’Connor 1999: pl. 1, figs 21-24), Lithocorythium ( Sugiyama 1994: pl. 5, fig. 2), and N e obotrys ( Nishimura & Yamauchi 1984: pl. 41, fig. 3). The sutures between the lobes result from the position of the arches, although this is not well illustrated in these photos. “Living” and protoplasm images were published for Amphimelissa ( Sashida & Uematsu 1994: fig. 3.11?; Suzuki & Not 2015: fig.8.11.15), Pylobotrys ( Zhang et al. 2018: 9, fig. 2.34), Botryocyrtis (Matsuoka 2017: fig. 30; Zhang et al. 2018: 9, fig. 2.35) and Monotubus ( Zhang et al. 2018: 9, fig. 2.36). Little is known about the evolutionary history of this family, except for visual hypotheses of Centrobotrys ( Riedel & Sanfilippo 1981: fig. 12.10) and the family’s genus level ( Petrushevskaya 1968).

VALIDITY OF GENERA

Amphimelissa

Large numbers of Amphimelissa setosa , the type species of this genus,have been illustrated from topotypic regions ( BjØrklund& Swanberg 1987; BjØrklund et al. 2015) to clarify the morphological variation within the genus. This species includes a morphotype with three or more rods derived from the initial spicular system ( BjØrklund & Swanberg 1987: figs 4.Q, 4.S, 4.W) and a tube or tube-like structure with a free V-rod ( BjØrklund & Swanberg 1987: figs 4.C, 4.W, 4.X). Petrushevskaya (1981: 326) revised the definition of Bisphaerocephalina as follows, translated using terminology from Sugiyama (1998):” Postcephalic lobe [note: lobe between A- and D-rods] slightly higher than the eucephalic lobe [note: lobe between A- and V-rods]; it may differentiate into a small tubule. Antecephalic lobe [note: lobe between V- and double L-rods] slightly differentiated [...] V-rod may be linked to a small tube [...] The apical horn and the appendages related to the D- and double L-rods may be well developed [...] ” These characters fall within the range of variation in Amphimelissa . The original description of Bisphaerocephalus by Popofsky (1908) is translated as follows: “ [...] Cephalis smooth, no horn, well differentiated from the thorax, which bears three laterally directed spines [note: spines directly connected from A- and double L-rods] in the collar area. Cephalis separated into two parts [note: postcephalic and eucephalic lobes] by a vertical stricture [...] From the upper part of the thorax to the lower part of the cephalis, the collar area is covered by a secondary mesh [note: antecephalic lobe, ...] ”. Popofsky (1908) reported no apical horn, but Petrushevskaya (1965: figs 9.1-9.3) shows wide variety in the lengths of the apical horn and appendages (see supporting image for Bisphaerocephalus ). These characters are also within the range of morphological variation in Amphimelissa . Glyco- botrys was proposed by Campbell (1951) to replace Lithobotrys Haeckel 1887 nec Ehrenberg 1844a, using the type species of Lithobotrys geminata . Campbell (1954: D143-144) explained that this genus has tubules and a fenestrated thorax. The topotype was identified in the Ehrenberg collection as L. geminata by Ehrenberg himself ( Ogane et al. 2009b: pl. 19, figs 7a-c), and surely can be identified as this species in the modern sense. The description by Campbell (1954) does not match either this topotype or the type-illustration ( Ehrenberg 1876: pl. 3, fig. 19). Foreman (1968: text-figs 11a-c) illustrated the cephalis structure of L. geminata . Based on these specimens, Glycobotrys lacks outcropped rods from the initial spicular system, except for the A-rod, but this genus has a larger postcephalic lobe than eucephalic lobe and a very small antecephalic lobe, as also seen in Amphimelissa at the genus level. Amphimelissa is the oldest available name among these genera.

Lithocorythium

The type-illustrations of both Lithocorythium ( Ehrenberg1854c: pl. 22, fig. 29a, 29b) and Phormobotrys ( Haeckel 1887: pl. 96, fig. 26) are in ventral view (showing V- and double L-rods), because the eucephalic lobe (smaller, between A- and V-rods) and postcephalic lobe (larger, between A- and D-rods) are both clearly visible. The first description was written in Latin by Ehrenberg (1847: 54) and is translated as follows: “ Shell with more than one stricture. Last segment whole. With no median appendages. Aperture latticed. ” The next description was written in German by Haeckel (1862: 330) and is translated as follows: “ Multi-segmented lattice shell, subdivided into three or more superposed irregular segments by two or more circular constrictions, with no lateral appendages and a constricted aperture covered by a lattice. ” The type-illustration of Lithocorythium demonstrates that these descriptions are incorrect: the postcephalic lobe is larger and without apical horn or appendages. The type-illustrations likely display the A-rod, which does not protrude from the cephalic wall, and D- and double L-rods, which are merged with the thoracic wall. The supporting image for Lithocorythium, cited by Sanfilippo et al. (1978: pl. 1, figs 4, 5), may not belong to Lithocorythium because the A-, D-, and double L-rods are extruded from the wall. The revised definition of Phormobotrys by Petrushevskaya (1981: 322) using the terminology ofSugiyama (1998) is translated as follows: “ Postcephalic lobe somewhat higher than the eucephalic lobe, with its length passing into a tube [...] No apparent apical horn or other appendages. Thorax well differentiated, but final segment rudimentary. Segments separated by deep internal septa. Aperture on the final segment enclosed by mesh. ” A comparison of the definition and type-illustrations of Lithocorythium and Phormobotrys shows that the only differences between these genera are the segments separated by deep internal septa and final segment rudimentary in the latter genus; however, both of these characters are inappropriate as genus criteria. Haeckel (1887: 1124), the author of Phormobotrys , mentioned the presence of a tube. As Lithocorythium does not appear to have a tube, their synonymy is in doubt. Phylogenetic studies are required to resolve this issue. The name Lithocorythium is older than Phormobotrys .

Neobotrys

Campbell (1954: D144) described Neobotrys as having an inner trellis consisting of a sagittal ring and appended spines. The sagittal ring is unusual; this description was probably derived from original remarks by Popofsky (1913: 320), whose definition of Neobotrys is translated as follows: “ Neobotrysidae with an inner spicule, composed of a sagittal ring supporting A-, D-, and double L-rods. The rods are enveloped by tubes [...] has two or three cephalic chambers. Based on these chambers, it should be related to the spyrids, after Haeckel [...] ”. As shown in specimens of the type species Neobotrys quadritubolosa (supporting image for Neobotrys in the Atlas ), the sagittal ring sensu Popofsky (1913 : pl. 30, fig. 4) corresponds to a deep constriction between the postcephalic lobe (between the A- and D-rods) and eucephalic lobe (between the A- and V-rods). The postcephalic and eucephalic lobes of the Pylobotrydidae have an A-rod, associated arches related with the A- and double L-rods, a double ap -arch that connects the L-rod and Al-arch within or attached to the wall ( Sandin et al. 2019: supplement). The illustrated specimen provided inPopofsky (1913) is in slightly oblique right dorsal side view, which overlooks several arches within the cephalis, which probably led to the incorrect description of a sagittal ring supporting A-, D-, and double L-rods. Xiphobotrys has a significant apical spine and appendages that are similar to those of Neobotrys . Unlike Neobotrys , Xiphobotrys lacks tubes in association with the very long A-, D-, V-, and double L-rods. Considering the close phylogenetic relationship between these two genera, they should be synonymized as a single genus. The name Neobotrys is older than Xiphobotrys .

Pylobotrys

The genera synonymized with Pylobotrys differ in the size and development of the postcephalic lobe (between A-and D-rods), antecephalic lobe (between V- and double D-rods), and tubes or appendages in the suture between the postcephalic lobe and thorax (terminology from Sugiyama 1998). Petrushevskaya (1981: 319) synonymized Acrobotrella, Acrobotrissa, and Neobotrys with Acrobotrys , but they require re-interpretation because the validated Acrobotrys is nomen dubium, and the type species have not been illustrated.

Acrobotrissa has two homonyms defined byHaeckel (1887: 1114; type species Acrobotrissa trisolenia ) and Popofsky (1913: 321; type species Acrobotrissa cribrosa ); their type images are documented in the Atlas . The validity of Acrobotrissa is discussed hereafter based on the former type species. Petrushevskaya (1981: 319-320) commented that Acrobotrys is a subjective synonym of Acrobotrissa because their characters are similar, and revised the definition of Acrobotrys , translated as follows: “[...] Postcephalic lobe with a long tube larger than the eucephalic lobe. Height of the eucephalic lobe with its own septa [...] Height of the antecephalic lobes slightly smaller than that of the eucephalic lobe, with a long tube on the ventral side. A rod crossing approx. the middle part of the postcephalic lobe. Collar structure differentiated, but not always very distinct. Tubes other than those of the A- and V-rods may be differentiated, i.e., tubes that are not connected to an internal spicule (in the suture between the postcephalic lobe and thorax) [...] ”. This description matches the type-illustration of Acrobotrissa ( Haeckel 1887: pl. 96, fig. 8), and therefore is considered the practical description of Acrobotrissa. Unlike Acrobotrissa, Acrobotrella is defined by the presence of two divergent tubes (apical and sternal) ( Haeckel 1887: 1114). This definition excludes morphospecies with a tube in the suture between the cephalic lobe and thorax (cf. type-illustration, Haeckel 1887: pl. 96, fig. 10). However, Acrobotrys trisolenia ( Haeckel 1887: pl. 96, fig. 8) and Acrobotrys disolenia ( Haeckel 1887: pl. 96, fig. 10) differ only in the presence of this tube. These two species presumably have a direct ancestral relationship; therefore, these genera should be merged into a single genus.

The definition of Pylobotrys was revised by Petrushevskaya (1981: 320), translated as follows: “ The postcephalic lobe, and also the galea , are subdivided into upper and lower parts. If the antecephalic lobe is well developed, and if the eucephalic lobe is divided into a collar and an upper part, then the cephalis may appear to be composed of multiple chambers, as reflected in the Haeckelian description and name.” This description of multiple chambers is probably the result of the complex initial spicular system. Petrushevskaya (1981: 320) noted that Pylobotrys is differentiated from Acrobotrissa (originally Acrobotrys ) in its shorter tubes and the structure of the cephalis, which is not separated from the thorax by a clear external constriction. Once Acrobotrella was synonymized with Acrobotrissa, the clear external constriction was removed as a genus criterion. The tube length is also insufficient for differentiating among these genera.

Ceratobotrys was established according to differences from Acrobotrissa (originally Acrobotrys ) including having apical and dorsal spines and two hollow latticed lateral spines, except for A-, D-, and double L-tubes ( Nishimura 1990: 169). The presence of these distinctive tubes, which are probably related to double L-rods, clearly differs from Acrobotrissa; however, if this character is applied for genus classification, the taxonomy of the Pylobotrydidae becomes complex, requiring the definition of many new genera. These characters are similar to those of Neobotrys , but the fundamental difference is that Neobotrys has distinctive A-, D-, and double L-rods outside the test. This difference does not allow to synonymize Ceratobotrys with Neobotrys . A remaining concern is that according to Popofsky (1913), Acrobotrissa cribrosa can be classified into Pylobotrys , with one or no tube on the postcephalic lobe; thus, this junior homonym is a synonym of Pylobotrys . No known specimens of A. cribrosa have a tube on the postcephalic lobe; therefore, the absence of a tube on the postcephalic lobe is a stable character. However, Acrobotrys chelinobotrys , described by Takahashi (1991: pl. 45, figs 22-24), is very similar to Ceratobotrys riedeli, the type species of Ceratobotrys, except for a closed postcephalic lobe in A. chelinobotrys . Considering this species-level difference, it is unlikely that A. cribrosa represents a separate genus from Acrobotrissa.

The oldest available genus among these groups is Pylobotrys , although the type species of Pylobotrys , P. putealis ( Haeckel 1887: pl. 96, fig. 21), has not been seen and was illustrated based solely on its first description by Haeckel.

Phylogenetic Molecular Lineage IV Sandin et al. (2019)

DIAGNOSIS. — The shell is generally robust with a completely grown last segment (either abdomen or thorax), which is very large relative to the cephalic size. The collar stricture is easily observable.

REMARKS

Lineage IV includes four superfamilies Cycladophoroidea , Sethoperoidea , Lithochytridoidea , and Pterocorythoidea . For all superfamilies, not including the Sethoperoidea , the placement in the Lineage IV relies upon molecular phylogeny ( Sandin et al. 2019), although PhyML bootstrap values (10 000 replicates, BS) and posterior probability (PP) score as>90% and>0.90, respectively. The diagnosis written above is mainly based on the common structures among the Cycladophoroidea , Lithochytridoidea and Pterocorythoidea , which are well recognized as members of a distinct molecular group.