Lophophaena undulatum ( Popofsky, 1913 ) 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 : 66-67

Lophophaena undulatum ( Popofsky, 1913) n. comb.

Plate 21, Figs. 4–5 .

Artopilium undulatum n. sp., Popofsky, 1913, pl. 36, figs. 4–5.

Artopilium undulatum Popofsky, Benson, 1966 , pl. 36, figs. 1–2.

Artopilium undulatum Popofsky, Renz, 1974 , pl. 16, fig. 14.

Lophocorys undulata (Popofsky) , Takahashi, 1991, pl. 40, figs. 9–10.

Peromelissa undulata (Popofsky) , Van de Paverd, 1995, pl. 71, figs. 12–13.

Lophophaena undulatum (Popofsky) , Renaudie, 2014, pl. 27, fig. 13.

Artopilium undulatum Popofsky, Trubovitz et al., 2020 , supplementary data 7.

Remarks. It is not entirely clear which genus this species should belong to, but it is included here in Lophophaena because it fits the basic genus definition, has been considered a lophophaenid by some authors, and because it has morphological similarities to many of the other Lophophaena species we encountered during this study. In the original illustration by Popofsky (1913), the spine that runs vertically alongside and extends upward from the cephalis is labelled the ventral spine, while the horizontally-oriented spine at the base of the cephalis is labelled the apical spine. It is our suspicion that the names of these two spines may be reversed, but since Popofsky’s type material is not available for inspection, it is not possible to draw this conclusion with absolute certainty. If the upward-trending spine is indeed the apical spine, this species would fit the definition of Lophophaena . However, if the apical spine is truly a horizontal spine in the neck area, this would be a characteristic unique among the lophophaenids and indeed suggest that this species belongs in a different family. This species was originally described as a theoperid (genus: Artopilium ) by Popofsky (1913), and many subsequent authors have upheld this designation. Takahashi (1991) states that Artopilium is a junior objective synonym of Triacarthus, and that this species, undulata , does not appear to be similar to the type species of that genus, Artopilium elegans . Takahashi therefore tentatively placed this species in the genus Lophocorys . The species was later moved to the genus Peromelissa by Van de Paverd (1995), but no discussion was provided to justify this. Here we follow the most recent genus designation of Renaudie 2014, and formally place the species in Lophophaena . In our opinion, this is the best genus for the species, provided that our interpretation of Popofsky’s illustration is correct.

Range. Late Miocene—Recent in the EEP. Lower limit not determined. See Table 1 .

Figures

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.