Lophophaena kaonashii, 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 : 60-61

Lophophaena kaonashii n. sp.

Plate 34, Figs. 1A – 8B .

urn:lsid:zoobank.org:act:8C9A5395-F8AD-43EE-BE0B-64C2173A99D2

Arachnocorys ? sp 2/3 partim., Trubovitz et al., 2020, supplementary data 7.

Diagnosis. Lophophaena with a heavily-silicified, spherical cephalis that has 1 or 2 conical horns unrelated to the apical spine, and a shouldered thorax with large pores around the top and no appendages.

Description. The cephalis of this species is spherical in shape and is more heavily silicified than the thorax. Well-preserved specimens show strongly-framed pores on the cephalis and many small bumps on the nodes of pores, which appear to have served as the bases of tiny, needle-like spines. 1, or rarely 2, prominent horns are present near the apex of the cephalis, but these are not related to the apical spine, which merges with the shell wall immediately above the collar structure and is so muted that it is difficult to detect. The thorax has a ring of large pores around the top where it connects to the cephalis. It reaches its widest point at the shoulders, and then tapers downward slightly. The lateral and dorsal spines merge with the thorax wall and do not form appendages. Pores on the thorax are small and tend to be more closely spaced than those on the cephalis.

Remarks. This species is structured similarly to Lithomelissa dybbuki (Pl. 19, Figs. 1–7 ), but differs in heaving a more heavily silicified cephalis, with large pores around the base. In addition, the apical spine of L. kaonashii does not pass through the center of the cephalis, disqualifying it from being in Lithomelissa .

Material examined. 16 specimens from samples 321-1337A-31X-6W, 4–6cm (Middle Miocene), 321-1337D-30H- 3, 103–104cm (Middle Miocene), 321-1337D-26H-3W, 142–144cm (Late Miocene), 321-1337D-23H- 6, 134– 137cm (Late Miocene).

Holotype. Pl. 34, Figs. 5A–B ; sample 321-1337D-23H- 6, 134– 137cm ; ECO-147; W22-4 .

Paratypes. (1) Pl. 34, figs. 9A–B; sample 321-1337D-26H- 3, 142–144cm; ECO-148; G8-4. (2) Pl. 34, figs. 4A–B; sample 321-1337A-31X-6, 4–6cm; ECO-151; O11-4. (3) Pl. 34, figs. 8A–B; sample 321-1337A-31X-6, 4–6cm; ECO-151; T 25-1. (4) Pl. 34, fig. 7; sample 321-1337A-31X-6, 4–6cm; ECO-151; U32-2. (5) [not figured] sample 321-1337D-26H- 3, 142–144cm; ECO-148; Z8-1.

Measurements. Cephalis height 34–41 (38)μm; cephalis width 30–40 (36)μm; neck width 25–34 (30)μm; width at shoulders 40–55 (48)μm. Based on 14 specimens.

Etymology. Named for the spirit Kaonashi (“No-Face”) in Hayao Miyazaki's animated film, Spirited Away.

Range. Middle—Late Miocene in the EEP, lower boundary not determined ( 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.