Lophophaena gozui, 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 : 57-58

Lophophaena gozui n. sp.

Plate 31, Figs. 1A – 6 .

urn:lsid:zoobank.org:act:95177882-DC83-4974-8370-E9B904F3E4BA unknown plagonid group C sp 32 cf, partim., Trubovitz et al., 2020, supplementary data 7.

Diagnosis. Lophophaena with a thumb-shaped cephalis that is relatively small compared to the thorax and has two prominent bladed horns on the dorsal and ventral sides.

Description. This species has heavily silicified cephalis with framed pores. The apical spine extends broadly upward as a strong bladed horn on the dorsal side, and a second bladed horn extends at a slightly lower angle from the ventral side of the cephalis. The top of the cephalis can exhibit several small thorns, but additional spines do not develop on top of the cephalis. The ventral spine is relatively long and needlelike when preserved. The cephalis is small compared to the thorax, which reaches approximately twice its width and is at least double the length of the cephalis (though a fully preserved thorax has not yet been observed, so it is likely even larger). Pores on the thorax can be approximately the same size as those on the cephalis, or slightly larger. The dorsal and lateral spines join the wall of the thorax and do not form prominent appendages, although a short tip may protrude outside the thorax (i.e., fig. 1).

Remarks. This species has a similar overall appearance to Lophophaena ushionii n. sp. (Pl. 31, Figs. 7A –11B), but differs in that the cephalis is much smaller, the thorax is relatively wider ( Figure 13 ), and it does not develop a third spine between the two prominent horns on the cephalis as does L. ushionii .

Material examined. 18 specimens from samples 321-1337A-31X-6W, 4–6cm (Middle Miocene), 321-1337D-26H-3W, 142–144cm (Late Miocene), and 321-1337D-23H- 6, 134–137cm (Late Miocene).

Holotype. Pl. 31, Figs. 1A–B ; sample 321-1337D-23H- 6, 134– 137cm ; ECO-147; O22-1.

Paratypes. (1) Pl. 31, fig. 2; sample 321-1337D-23H- 6, 134–137cm; ECO-145; Z26-1. (2) Pl. 31, fig. 5; sample 321-1337D-23H- 6, 134–137cm; ECO-145; U8-3. (3) Pl. 31, figs. 4A–B; sample 321-1337D-26H- 3, 142–144cm; ECO-148; Y41-1. (4) Pl. 31, fig. 6; sample 321-1337D-26H- 3, 142–144cm; ECO-148; U32-1. (5) [not figured] sample 321-1337D-23H- 6, 134–137cm; ECO-145; H13-3.

Measurements. Cephalis height 38–42 (40)μm; cephalis width 30–36 (34)μm; thorax width 71–110(87) μm; ratio of thorax:cephalis width 2.0–3.1 (2.5). Based on 12 specimens. Note: thorax width should be considered the minimum width, as the thorax is typically not fully preserved. In the two specimens that appeared to have a nearlycomplete thorax, its width was 105 and 110 microns.

Etymology. Named for the ox-headed demon, Gozu, that guards the gates of hell in Japanese Buddhism, for its resemblance to an ox.

Range. Middle– Late Miocene, 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 6. Internal skeletal structure of Arachnocorallium calvata (Haeckel, 1887) Petrushevskaya, 1971.

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

FIGURE 13. Chart illustrating the differences between Lophophaena gozui n. sp. (orange diamonds) and L. ushionii n. sp. (green squares), in terms of cephalis height and the ratio between thorax and cephalis width. L. gozui has a shorter average cephalis height (40 microns) compared to L. ushionii (average cephalis height = 54 microns). In addition, the thorax is proportionally wider compared to the cephalis in L. gozui (average ratio of thorax:cephalis width = 2.5). L. ushionii has a proportionally narrower thorax (average ratio of thorax: cephalis width = 1.5).