Pelagomanes thaumasia ( Caulet, 1991 ) Trubovitz, Sarah, Renaudie, Johan, Lazarus, David & Noble, Paula, 2022

Trubovitz, Sarah, Renaudie, Johan, Lazarus, David & Noble, Paula, 2022, Late Neogene Lophophaenidae (Nassellaria, Radiolaria) from the eastern equatorial Pacific, Zootaxa 5160 (1), pp. 1-158 : 83

Pelagomanes thaumasia ( Caulet, 1991) n. comb.

Plate 39, Figs. 10A –11.

Lophophaena? thaumasia n. sp., Caulet, 1991, pl. 2, figs. 5–6.

Lophophaena? thaumasia Caulet, Renaudie, 2014 , pl. 33, fig. 4.

Lithomelissa? kozoi cf sp 4 (partim), Trubovitz et al., 2020, supplementary data 7.

Remarks. P. thaumasia has a strong tribladed apical horn, which differentiates it from P. kozoi (Pl. 39, Figs. 1–6 ) and P. stigi (Pl. 39, Figs. 7–9 ). It has randomly arranged pores on the thorax, which do not align along ribs, as in P. morawanensis (Pl. 40, Figs. 4A – 6 , 9 , 11–12) and P. cantharoides (Pl. 40, Figs. 1–3 , 7–8 , 10 , 14 ). This species lacks strong ribs and prominent teeth at the base of the thorax. The specimens observed in the EEP appear to have a slightly more narrow thorax than those observed by Renaudie in the Southern Ocean, and those figured by Caulet (1991).

Range. Middle Miocene—Pleistocene in the EEP ( Table 1 ).

Figures

FIGURE 1. Diagram illustrating the general skeletal morphology of Lophophaenidae, and terminology used in this manuscript. Dashed lines indicate spines that are not visible from the angle shown, as they extend into the skeleton. An example specimen of Lophophaena casperi n. sp. is included for comparison to the diagrams.

FIGURE 2. Relative abundance of specimens and taxa belonging to Plagiacanthoidea and Lophophaenidae per sample, from IODP Site U1337 in the EEP over the last ~10 Ma. The relative percentages of total taxa are represented by the blue lines and the red lines represent the percentages of total specimens (triangles = Plagiacanthoidea; circles = Lophophaenidae). The Plagiacanthoidea was among the most abundant and speciose of radiolarian groups encountered in Trubovitz et al. (2020), with at least 10% of the specimens and 20% of the taxonomic richness in every sample. Within the Plagiacanthoidea, lophophaenids consistently made up the majority of specimens (~67%) and taxa (~61%). Data are from Trubovitz et al. (2020).

FIGURE 3. Locality map of IODP Site U1337, where all samples for this study were collected. Map from Google EarthTM.

FIGURE 4. Examples of specimen measurements discussed in the Systematic Paleontology section of this study.

FIGURE 5. Internal skeletal structure of Amphiplecta acrostoma Haeckel, 1887.

FIGURE 6. Internal skeletal structure of Arachnocorallium calvata (Haeckel, 1887) Petrushevskaya, 1971.

FIGURE 7. Internal skeletal structure of Arachnocorys umbellifera (Haeckel, 1862) Petrushevskaya, 1971.

FIGURE 8. Internal skeletal structure of Botryopera amabie n. sp.

FIGURE 9. Internal skeletal structure of Ceratocyrtis sp. C.

FIGURE 10. Internal skeletal structure of Lithomelissa alkonost n. sp.

FIGURE 14. Chart illustrating the different cephalis sizes in Lophophaena shishigae n. sp. and Arachnocorys jorogumoae n. sp. The yellow circles indicate L. shishigae, with a small cephalis, and the purple triangles represent A. jorogumoae, with a significantly larger and proportionally higher cephalis.