Larcopyle buetschlii orion, Zhang, Lanlan & Suzuki, Noritoshi, 2017

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 : 34-36

Larcopyle buetschlii orion n. subsp.

Figure 21

zoobank.org/ 2AAB8F10-A6CB-4ABC-8954-CA404AEB86AA

? 1978 Prunopyle or Larcopyle indet. Riedel and Sanfilippo, pl. 2, fig. 16 (only).

Etymology. The Latin masculine noun “Orion” (- onis), a name of one of the Giants of Greek mythology.

Holotype. Specimen in Figure 21.15-16 from the sample YDY05-01.

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Paratype. Specimen in Figure 21.11-12 from the sample YDY05-01.

Description. Test is flat and ellipsoid in shape, with a pylodiscid-type central combination, two or three large pseudo-concentric shells, and an outermost coverage shell with coarse pores. The Lt-axis in Type 1 coordinates is nearly parallel to the shortest axis (Ug-axis in Type 2 coordinates) of the test. The 1st pseudo-concentric shell appears as a rounded square in Lt-view and as an elongated oblong form in Sg- and Pl-views. The 2nd pseudo-concentric shell develops along the Lt-axis from both ends of the 1st pseudo-concentric shell in Type 1 coordinates. Pillar beams extend from both ends of the 1st pseudo-concentric shell to connect directly with the 2nd pseudo-concentric shell. The twin gates inside the 2nd pseudo-concentric shell are visible from the lateral side of the test. The 3rd pseudo-concentric shell develops outside of the 2nd pseudo-concentric shell, which is connected with the 3rd by numerous pillar beams. At least four fine, straight rods extend from each corner of the 2nd pseudo-concentric shell. These pillar beams further elongate outside of the 3rd pseudo-concentric shell, and have a spiny appearance. The outermost coverage shell comprises thin pore frames and rough surfaces with variable sizes and shapes of pores. Short radial spines or by-spines emerge from some pillar beams from the 2nd pseudo-concentric shell. A pylome is not present.

Remarks. Larcopyle buetschlii orion n. subsp. is primarily characterized by its large test (ca. 200 μm in the longest axis (Ug-axis) in Type 2 coordinates, 1.5–2.0 times larger than other Larcopyle buetschlii subspecies. The type specimen of Larcopyle buetschlii buetschlii is as large as this new subspecies, nearly 200 μm in the longest axis (see the original description of Dreyer, 1889). Larcopyle buetschlii orion n. subsp. is distinguishable from large L. buetschlii buetschlii based on the latter’s very small 1st pseudo-concentric shell, tightly revolved girdles, and its thick, robust outermost coverage shell with fine pores and a pylome. Larcopyle buetschlii orion n. subsp. differs from Larcopyle cervicornis ( Haeckel, 1887) based on the latter’s more laterally elongated 1st pseudo-concentric shell and rougher pores, and from Larcopyle buetschlii chenmuhongi n. subsp, based on the latter’s more tightly coiled girdles and smaller shell.

Dimensions. Based on the holotype specimen. The width of the central combination (S1a): ca. 16.3 μm; The length and width of the 1st pseudo-concentric shell: 66.8 μm and 57.1 μm; The length and width of the 2nd pseudo-concentric shell:

ZHANG & SUZUKI: TAXONOMY OF HOLOCENE PYLONIOID

116.2 μm and 103.3 μm. The length and width of the outermost coverage shell: 170.4 μm and 137.3 μm. The ratio of length to width of the outermost coverage shell: ca. 1.2.

Figures

FIGURE 21. Photographs of the encountered morphotypes of Larcopyle buetschlii orion n. subsp. All are Fr-view at Type 2. Scale bar equals 0.1 mm. All specimens are from YDY05-01.