Lophophaena macrencephala Clark and Campbell, 1945

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 : 63

Lophophaena macrencephala Clark and Campbell, 1945 partim.

Plate 21, Figs. 7A – 8B .

Lophophaena macrencephala n. sp., Clark and Campbell, 1945, pl. 7, figs. 6 and 9 (non figs. 7 and 8).

non Lophophaena sp. B , Petrushevskaya, 1971, pl. 56, figs. 1–3.

non Lophophaena macrencephala Clark and Campbell, Dzinoridze et al., 1978 , pl. 29, fig. 20; pl. 32, fig. 36.

non Lophophaena macrencephala Clark and Campbell, Petrushevskaya and Kozlova, 1979 , figs. 348–349.

Lophophaena macrencephala?, Renaudie, 2014 , pl. 23, fig. 5.

Lophophaena macrencephala? Clark and Campbell, Trubovitz et al., 2020 , supplementary data 7.

Remarks. There is a good deal of confusion regarding this species, and poor documentation in the literature. Clark and Campbell (1945) listed this species under the generic name Lophophaena , and the subgeneric name Lophophaenula . Because Campbell (1954) later synonymized the subgenus Lophophaenula under the genus Lophophaena , we drop the subgenus designation from the name. Clark and Campbell (1945) illustrated four specimens to accompany their species description. It is our opinion that at least two different species are included in these illustrations (pl. 7, figs. 6–9 in Clark and Campbell, 1945). Specimens 6 and 9 have a globular cephalis, slightly wider than the shoulder area of the thorax. However, specimens 7 and 8 have a relatively small, thumb-shaped cephalis, that is slightly narrower than the shoulders of the thorax. Specimen 7 also exhibits some cephalic pores more than twice the diameter of any pores on the other specimens. All specimens display a variable number of cephalic horns, and are broken in a way that does not show the full thorax. In their species description, Clark and Campbell (1945) note: “The 4 shells which we illustrate and assign to the present species may not all belong together. They have in common the swollen cephalis subequal in size, and very nearly in shape, but the horns are different. One of them (fig. 9) has no horns at all, while the others have one (fig. 8) or more (figs. 6–7). The last are considered to be typical of the species.” Although we disagree with Clark and Campbell (1945) that all the shells exhibit a “swollen” cephalis and are similar in shape or size, we do agree that these four specimens do not belong to the same species. Specifically, the specimens considered “typical” by Clark and Campbell (figs. 6 and 7) are in our opinion almost certainly different species. Furthermore, the presence of multiple spines on the cephalis alone is not a sufficient reason to group the specimens in fig. 6 and fig. 7. Petrushevskaya and Kozlova (1979) ’s concept of L. macrencephala includes Clark and Campbell (1945) ’s figs. 7–8, but excludes figs. 6 and 9. Petrushevskaya and Kozlova (1979) consider this species to be similar to L. apiculata (= L. galeaorci ), but is overall smaller in size. The specimens questionably assigned to Lophophaena macrencephala in Trubovitz et al. (2020) are most similar to Clark and Campbell (1945) ’s illustrated specimens in figs. 6 and 9, in terms of segment proportions and pore size. Clark and Campbell’s fig. 6 and fig. 9 appear to most closely match their own description of the species, as these could be described as having a “globular” or “swollen” cephalis. The specimens in figs 7–8 appear to belong to two different species due to the different pores sizes on the cephalis and the size of the cephalis itself, and so we do not follow Petrushevskaya and Kozlova (1979) ’s revision of the species concept. As they also listed Petrushevskaya (1971) ’s Lophophaena sp. B in their synonymy, we examined this specimen and concluded that it does not fit our concept of L. macrencephala . Instead, we adopt Clark and Campbell’s fig. 6 and fig. 9 as the concept for Lophophaena macrencephala . In addition to some of the type specimens, our illustrations here and in Trubovitz et al. (2020), Renaudie (2014) also illustrated a similar specimen as Lophophaena macrencephala ? (pl. 23, fig. 5 in Renaudie, 2014) that could be conspecific with ours, and our accepted part of Campbell and Clark (1945) ’s concept. To fully resolve this concept however, the original type material will need to be examined, which is beyond the scope of this project.

Range. Late Miocene, EEP ( Table 1 ).

Figures

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

FIGURE 8. Internal skeletal structure of Botryopera amabie n. sp.