Lophophaena radians Ehrenberg, 1874

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 : 75

Lophophaena radians Ehrenberg, 1874

Lophophaena radians n. sp., Ehrenberg, 1874, p. 243 [not figured].

Lophophaena radians Ehrenberg, Ehrenberg, 1876 , pl. 8, figs. 7–9.

Lophophaenoma radians (Ehrenberg) , Petrushevskaya, 1981, p. 86, fig. 78.

? Lophophaena lynx n. sp., Ehrenberg, 1876, pl. 8, fig. 13.

Lophophaena radians Ehrenberg, Kamikuri, 2015 , pl. 13, fig. 30.

Lophophaena radians Ehrenberg, Ogane et al., 2009 , pl. 3, figs. 3a–b, 5a–d; pl. 79, figs. 4a–c.

Remarks. This species has a very convoluted history in the literature.After it was described and figured by Ehrenberg (1874, 1876), Haeckel (1887) split the concept into two separate species, apparently on the basis of isolated versus interconnected horns on the cephalis. He asserted that Ehrenberg (1876) ’s pl. 8, figs. 7–8 (with interconnected spines) should be considered a junior synonym of Lophophaena circumtexta Haeckel (not to be confused with Arachnocorys circumtexta Haeckel ), which to our knowledge was never illustrated beyond Ehrenberg’s illustrations of Lophophaena radians . Haeckel (1887) retained the name Lophophaena radians for Ehrenberg (1876) ’s pl. 8, fig. 9 only (which is identical to figs. 7–8, except for the lack of interconnected horns), and questionably synonymized it with Lophophaena lynx Ehrenberg. L. lynx does indeed appear to be very similar in overall shape and proportions to Lophophaena radians Ehrenberg 1876 , pl. 8, fig. 9, but may have fewer horns and is smaller in size. Therefore, it is questionably included in our synonymy. It is our opinion that all three specimens of L. radians illustrated by Ehrenberg (1876) are the same species, so we do not adopt Haeckel’s revision or synonymy here. Interconnections between horns can sometimes be an ontogenetic character, as evidenced by other lophophaenid species, so should not be the sole basis of splitting species concepts. Petrushevskaya (1971) designated L. circumtexta (junior synonym: L. radians Ehrenberg ) as the type species of Lophophaenoma , which she elevated to the genus rank after it was described as a subgenus of Lophophaena by Haeckel (1887). However, in the taxonomic remarks section, she states that L. radians Ehrenberg is the type species of Lophophaenoma , and that L. circumtexta Haeckel is its junior synonym. Petrushevskaya (1971) also considered all specimens figured by Ehrenberg (pl. 8, figs. 7–9) to be part of L. radians , including forms with and without interconnected cephalic spines (contrary to Haeckel). Later, Petrushevskaya (1981) found that Lophophaenoma should be demoted back to a subgenus as it is largely a junior synonym of Arachnocorys , although some species in Lophophaenoma should be placed in Peromelissa or Lophophaena instead. It is unclear to which genus Petrushevskaya (1981) thought L. radians should belong, since it was the type species of a genus determined to be a junior synonym of Arachnocorys (p. 86–87), but figured as an example of Lophophaenoma with the genus name Lophophaena (fig. 78). Here we do not believe this species should be in Arachnocorys , because it lacks gaps between the cephalis and thorax and has a more cylindrical, ribless thorax than other species in Arachnocorys . Petrushevskaya (1971) also considered L. radians to be different from Arachnocorys for its lack of gaps between cephalis and thorax. Kamikuri (2015) was the most recent author to illustrate this species; he did so under its original name, Lophophaena radians Ehrenberg. Here we follow Kamikuri (2015) and also use the original name, although no specimens were observed during our study. Other than Kamikuri (2015) and the re-illustrations of Ehrenberg’s collection by Ogane et al. (2009), we do not know of other photographs of L. radians , so this species is in need of additional documentation to be fully understood.