Larcopyle pulchella, Zhang & Suzuki, 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 : 37-38

Larcopyle pulchella n. sp.

Figure 18.19-22

zoobank.org/ E6AD5779-03F0-4709-9EB2-235B05CBC4A0

Etymology. The Latin adjective “pulchellus” (-a, - um), meaning pretty.

Holotype. Specimen in Figure 18.19-20 from the sample YDY05-01.

Paratype. Specimen in Figure 18.21-22 from the sample YDY05-01.

Description. Test is flat and ellipsoid in shape and consists of a pylodiscid-type central combination, one ellipsoid pseudo-concentric shell, and an outermost coverage shell with a wide bore pylome. Additional caps may develop at the apex and pylomate ends in mature forms. The central combination appears spherical or rectangular in shape depending on the orientation of observation. The 1st pseudo-concentric shell appears rectangular-ellipsoid in shape. The 1st pseudo-concentric shell is connected with the central combination by at least eight rods from each edge of the central combination. No pylomate structure exists in the 1st pseudo-concentric shell. The longest axis of the 1st pseudo-concentric shell is parallel to that of the central combination. The outermost shell is latticed and is also rectangular-ellipsoid in shape; its longest axis is parallel to the longest axis of the 1st pseudo-concentric shell. A bore pylome is present during the ontogenetic stage with a thin-walled outermost shell; this pylome is enclosed in the thick-walled ontogenetic stage. The sizes of the pores of the 1stpseudo-concentric shell and the outermost shell are similar, ranging from 12 to 18 μm in diameter.

Remarks. Larcopyle pulchella n. sp. is characterized by a rectangular-ellipsoid 1st pseudo-concentric shell. The developmental stage of the outermost shell varies. This new species differs from “ Prunopyle ” longiseta ( Dreyer, 1890) in that the latter has a more spherical outermost coverage shell and a larger bore pylome. This new species is different from Larcopyle peregrinator Lazarus, Faust, and Popova-Goll, 2005 , in that the latter has a more robust outermost coverage shell with deeply depressed pores and numerous spinules around the mouth of the bore pylome.

Dimensions. Based on the holotype specimen. The length and width of the 1st pseudo-concentric shell: 42.5 μm and 31.9 μm; The length and width of the outermost coverage shell: 74.3 μm and 49.7 μm. The ratio of length to width of the outermost coverage shell: ca. 1.5.

Figures

FIGURE 18. Photographs of the encountered morphotypes of Larcopyle. 1-6, Larcopyle variabile (Dreyer, 1889) sensu emend.; 7-12, Larcopyle molle n. sp.; 13-18, Larcopyle eccentricanoides n. sp.; 19-22, Larcopyle pulchella n. sp. All are Fr-view at Type 2. Scale bar equals 0.1 mm. All specimens are from YDY05-01.

FIGURE 19. Photographs of the encountered morphotypes of Larcopyle buetschlii buetschlii Dreyer, 1889, sensu stricto. All are Fr-view at Type 2. Scale bar equals 0.1 mm. All specimens are from YDY05-01.

FIGURE 20. Photographs of the encountered morphotypes of Larcopyle buetschlii chenmuhongi n. subsp. All are Fr- view at Type 2. Scale bar equals 0.1 mm. All specimens are from YDY05-01.

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.

FIGURE 22. Photographs of the encountered morphotypes of Sphaeropylolena laxa n. sp. All are Fr-view at Type 2. Scale bar equals 0.1 mm. All specimens are from YDY05-01.