Lithomelissa sp.

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 : 44-45

Lithomelissa sp. cf. L. ehrenbergi Bütschli, 1882

Plate 15, Fig. 8A–B ; Plate 16 Fig. 9A–B .

Lithomelissa cf. ehrenbergi, Trubovitz et al., 2020 , supplementary data 7.

Remarks. This species resembles Lithomelissa ehrenbergi Bütschli, 1882 (Pl. 15, Figs. 7A–C ) except that the wall of the cephalis is thinner and the cephalis is more elongated. It differs from Lithomelissa mitra Bütschli (Pl. 15, Figs. 4A–6) in that the cephalis is proportionally larger. This species is similar to Lithomelissa alkonost n. sp. (Pl. 16, Figs. 1A–7B), but differs in that the neck area is more clearly constricted. The pores on the cephalis and thorax are more regularly distributed and typically larger than in L. alkonost n. sp. and L. sirin n. sp. (Pl. 17, Figs. 1 –11B). Appendages on the thorax are typically very strong and bladed, similar to L. ehrenbergi and L. mitra , but different from the thin, conical spines typical in L. sirin and the usually short thoracic spines on L. alkonost . Despite their differences, all of these species are apparently closely related and will require further study to determine true species-level distinctions versus intraspecific morphological variation.

Material examined. 65 specimens observed from samples 321-1337A-16H- 6, 121–124cm (Late Miocene), 321-1337A-12H-5, 23–26cm (Late Miocene), 321-1337A-10H-2, 91–94cm (Early Pliocene), 321-1337A-7H- 6, 104–107cm (Early Pliocene), and 321-1337A-5H-5, 11–14cm (Late Pliocene).

Range. Late Miocene—Late Pliocene, 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 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.