Tetrapyle circularis Haeckel, 1887

Zhang, Lanlan & Suzuki, Noritoshi, 2017, Taxonomy and species diversity of Holocene pylonioid radiolarians from surface sediments of the northeastern Indian Ocean, Palaeontologia Electronica (Cambridge, England: 2003) 7 (8), pp. 1-68 : 15-18

Tetrapyle circularis Haeckel, 1887

Figures 8 , 9

1887 Tetrapyle circularis Haeckel , p. 645, pl. 9, fig. 8.

1912 Spironium cochelarium Popofsky , p. 153, text-fig. 74.

1972b Tetrapyle octacantha Müller ; Ling, p. 168, pl. 2, fig. 3.

ZHANG & SUZUKI: TAXONOMY OF HOLOCENE PYLONIOID

1977 Tetrapyle sp. cf. T. octacantha Müller ; Kling, pl. 1, fig. 14.

1980 Tetrapyle octacantha Müller ; Boltovskoy and Riedel, p. 120, pl. 4, fig. 11.

1981 Tetrapyle octacantha Müller ; Takahashi and Honjo, p. 150, pl. 6, fig. 6 (only).

1982 Tetrapyle octacantha Müller ; Poluzzi, p. 59, pl. 9, figs. 3, 6, 10 (only).

1984 Tetrapyle octacantha Müller ; Nigrini and Lombari, p. S87-88, pl. 12, figs. 3a, b.

1984a Octopyle stenozona Haeckel ; Nishimura and Yamauchi, pl. 3, fig. 13.

1984b Tetrapyle octacantha Müller ; Nishimura and Yamauchi, p. 42, pl. 17, figs. 7, 12.

1985 Octopyle stenozona Haeckel ; Boltovskoy and Jankilevich, pl. 3, fig. 22.

? 1984b Tetrapyle octacantha Müller ; Nishimura and Yamauchi, pl. 43, fig. 13.

1986 Tetrapyle octacantha Müller ; Yamauchi, pl. 4, fig. 13.

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1990 Octopyle stenozona Haeckel ; Blueford, Gonzales, and Scoy, pl. 1, fig. 7.

sensu emend.

1990 Tetrapyle circularis Haeckel ; Tan and Chen, p. 113-114, text-fig. 4, pl. 2, figs. 1-3.

1990 Octopyle circinata Tan and Chen , p. 118, text-fig. 10.

1990 Tetrapyle circularis Haeckel ; Yeh and Chen, pl. 3, fig. 10.

1991 Tetrapyle octacantha Müller ; Takahashi, p. 90, pl. 23, fig. 10.

1992 Tetrapyle octacantha Müller ; Alexandrovich, pl. 4, fig. 2.

? 1992 Tetrapyle octacantha Müller ; Haslett, fig. 1.a.

1993 Octopyle stenozona Haeckel ; Sharma and Singh, pl. 2, fig. 19.

1994 Octopyle stenozona Haeckel ; Haslett, p. 132, pl. 5, fig. 3 (only).

1994 Pyloniid, gen. et sp. Kim and Kim, pl. 1, fig. 14.

1994 Tetrapyle octacantha Müller ; Iijima, Takahashi, Ittekkot, and Nair, fig. 5.4 (only).

1994 Tetrapyle octacantha Müller ; Kim, Park, and Park, pl. 2, fig. 5.

1995 Tetrapyle octacantha Müller ; van de Paverd, p. 193-194, pl. 56, figs. 1, 4, 7.

1996 Tetrapyle circularis Haeckel ; Chen and Tan, p. 193-194.

1996 Octopyle circinata Tan and Chen ; Chen and Tan, p. 194, pl. 21, figs. 9, 10.

1998 Pyloniid group. Danelian and Frydas, p. 140, pl. 1, fig. 7.

1998 Tetrapyle octacantha Müller ; Shinjo, Motoyama, Nakamura, Takaki, Nishida, Morii, and Tanaka, pl. 1, fig. 7.

1998 Tetrapyle circularis Haeckel ; Tan, p. 253- 254, text-fig. 238.

1999 Tetrapyle octacantha Müller ; Molina-Cruz, Welling, and Caudillo-Bohorquez, pl. 1, figs. 1, 2.

1999 Tetrapyle octacantha Müller ; Sashida, and Kurihara, p. 139, 141, figs. 8.3, 8.4?, 8.11, 8.12?

2001 Tetrapyle octacantha Müller ; Matsuoka, Yoshida, Hasegawa, Shinzawa, Tamura, Sakumoto, Yabe, Niikawa, and Tateishi, pl. 2, fig. 2 (only).

2003 Octopyle stenozona Haeckel ; Itaki and Ikehara, fig. 4.h.

2005 Tetrapyle octacantha Müller ; Motoyama, and Nishimura, fig. 9.12 (only).

2007 Tetrapyle octacantha Müller group; Itaki, Komatsu, and Motoyama, pl. 1, figs. 8-10 (only).

2007 Tetrapyle octacantha Müller ; Kurihara, Uchida, Shimotani, and Matsuoka, fig. 5.2.

2008 Tetrapyle octacantha Haeckel (wrong author’s name); Itaki, Minoshima, and Kawahata, pl. 2, fig. 9 (only).

2008 Tetrapyle octacantha Müller ; Kamikuri, Motoyama, and Nishimura, pl. 1, fig. 33.

2008 Tetrapyle octacantha Müller ; Okazaki, Takahashi, and Asahi, pl. 1, figs. 11-12

2009 Tetrapyle octacantha Müller group; Itaki, pl. 10, figs. 2a-c, 6, 8.

2009b Schizomma quadrilobum Ehrenberg ; Suzuki, Ogane, Aita, Sakai, and Lazarus, pl. 70, figs. 6a-7d (type specimen in the Ehrenberg collection).

2010 Tetrapyle circularis Haeckel ; Suzuki, and Kanie, pl. 9, fig. 15.

2011 Octopyle stenozona Haeckel ; Pandey, p. 44, pl. 2, fig. H.

2014c Tetrapyle octacantha Müller ; Matsuzaki, Nishi, Suzuki, Kawate, Takashima, and Sakai, pl. 1, fig. 21.

2015a Tetrapyle octacantha Müller group; Matsuzaki, Suzuki, and Nishi, p. 34-35, figs. 6.1, 6.3, 6.5.

2015b Tetrapyle octacantha Müller group; Matsuzaki, Suzuki, Nishi, Hayashi, Gyawali, Takashima, and Ikehara, figs. 7.8, 7.11, 7.12.

Description. The test is circular in Fr-view (ratio of length to width: ca. 1.0–1.3) and comprises the pyloniid central combination and five girdles. Some fine and short spines are scattered across the ourtermost girdle surface. The polar beams are not always connected to the outermost girdle. The twin gates of the S3a-girdle (G4 girdle) appear kidney-shaped (ratio of width to height: ca. 1.4–2.0) in Fr-view. Two to three roundish and relatively large pores are visible from Pr-view for each girdle.

Remarks. Tetrapyle circularis is characterized by a curved outline on both its joint and cap components; this curved outline is an important feature for distinguishing this taxon from other Tetrapyle species. Tetrapyle circularis was previously regarded as Tetrapyle octacantha or “ Schizomma quadriloba .” The taxon name “ Schizomma quadriloba ” has been used to refer to any kidney-shaped pyloniids without portal-spines, but the lectotype of this species from the Ehrenberg collection illustrated by Suzuki et al. (2009b) consists of only a central combination and G1 and G2 girdles; thus, T. circularis is fully differentiated from “ Schizomma quadriloba .” This species apparently represents a juvenile form of pylonioids. Tetrapyle circularis is easily distinguished from T. octacantha based on the four long portal-spines of the latter along the periphery of its outermost girdle. Tetrapyle circularis is differentiated from Tetrapyle fruticosa based on the straighter outline on both joint and cap components in the latter. The oldest record of a probable T. circularis is from the lower Pliocene Ikego Formation of the Miura Group, Kanto, Japan ( Suzuki and Kanie, 2010), but this specimen differs slightly from typical T. circularis from the modern ocean in that the former’s outermost girdle is more elongate. The “ Tetrapyle octacantha ” specimens from the Southern Ocean ( Brathauer, 1996, plate 2, figure 2) and the Southwest Pacific ( Cortese and Abelmann, 2002, plate 2, figure 24) are similar to T. circularis with a rounded outermost girdle on Fr-view; however, the former differs from the latter in its notably spiny appearance and more spherical pseudo-concentric shells in its inner side. “ Spironium cochearium Popofsky, 1912 ” seemed to be differentiated from T. circularis by its more elongated outline. However, we measured the ratio of the test between probable “ S. cochelarium ” and T. octacantha , concluding in the same species due to their gradual changes.

Figures

FIGURE 8. Photographs of the encountered morphotypes of Tetrapyle circularis Haeckel, 1887. All are Pl-view at Type 1, Fr-view at Type 2. Scale bar equals 0.1 mm. All specimens are from YDY05-01.

FIGURE 9. Photographs of the encountered morphotypes of Tetrapyle circularis Haeckel, 1887. All are Pl-view at Type 1, Fr-view at Type 2. Scale bar equals 0.1 mm. All specimens are from YDY05-01.