Botryopera amabie, 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 : 25-26

Botryopera amabie n. sp.

Plate 7, Figs. 1A – 6 .

urn:lsid:zoobank.org:act:FD765F95-F2EE-426C-9198-08D087AF90A9

Diagnosis. Lophophaenid with characteristics shared by Botryopera species, as well as a narrow, elongated overall shape, thickly-silicified neck region, distinct apical spine fused to the cephalis wall, and dendritic axobate extending into the thorax.

Description. The cephalis of this species is somewhat thumb-shaped and elongated; it is similar in width to the thorax, giving the skeleton an overall subcylindrical shape. The apical spine runs alongside the wall of the cephalis and terminates in a relatively short and thin apical horn. Besides the apical horn, the cephalis has no other spines. The shell wall attains peak thickness where the thorax attaches to the cephalis, and thins both upward and downward. This species has an atypical pore structure on the shell wall, compared to most other lophophaenids observed in this study. The unframed straight-walled pores resemble those of other described Botryopera species. The neck area exhibits the largest pores on the skeleton, which decrease in size in both upwards and downwards. Dorsal and lateral spines pierce the thorax but do not form long wings or external spines.

Remarks. This species differs from described Botryopera taxa in that it has a short, thin apical spine that runs along the side of the cephalis (similar to Lophophaena ). However, the dendritic axobate is an indicator that this species does not belong in Lophophaena . It differs from typical Antarctissa species in the elongated shape of the cephalis, and the single horn on the cephalis that is an extension of the apical spine.

Material examined. 10 specimens from samples 321-1337A-35X- 1, 106–108cm (Middle Miocene), 321- 1337A-31X-6W, 4–6cm (Middle Miocene), 321-1337D-30H-3, 103–104cm (Middle Miocene), and 321-1337D-26H-3W, 142–144cm (Late Miocene).

Holotype. Pl. 7, Fig. 4A–B ; sample 321-1337D-30H- 3, 103– 104cm ; ECO-150; O43-4.

Paratypes. (1) Pl. 7, Fig. 5 ; sample 321-1337D-30H- 3, 103–104cm; ECO-149; D4-3. (2) [not figured] sample 321-1337D-30H- 3, 103–104cm; ECO-149; O36-2.

Measurements. Cephalis height 40–47 (43)μm; minimum thorax length (of specimens not obviously broken) 40–70 (50)μm; width of thorax at shoulders 38–45 (41)μm. Based on 10 specimens.

Etymology. Named for the Japanese yokai, Amabie, who emerges from the sea to tell the future and whose image can protect people from disease.

Range. Middle–Late Miocene in the EEP; lower limit was 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 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.