Lophophaena sp. A

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 : 69

Lophophaena sp. A

Plate 36, Figs. 1A – 2B .

Lophophaenoma sp. , Petrushevskaya, 1971, pl. 57, fig. 7.

non Lophophaena triangula n. sp., Funakawa, 1994, p. 466, 468; pl. 8, figs. 31–4b.

unknown plagonid group C sp 75, Trubovitz et al., 2020, supplementary data 7.

Remarks. The specimens we observed in the EEP closely resemble the specimen illustrated as Lophophaenoma sp. by Petrushevskaya (1971). Funakawa (1994) questionably synonymized Petrushevskaya’s specimen with a new species, Lophophaena triangula . However, it is our opinion that the specimens figured by Funakawa differ in cephalis shape and overall size from Petrushevskaya’s Lophophaenoma sp. specimen. Therefore, we suggest that our two specimens are conspecific with Petrushevskaya’s Lophophaenoma sp. , but none of these are the same as Lophophaena triangula Funakawa. This species was extremely rare in our material, so unfortunately we are not able to provide a formal description here (only two specimens were observed). As we do not accept Lophophaenoma as a valid genus, Lophophaena is used instead. However, the strong bladed feet on this species is not typical of Lophophaena , so future study of more complete specimens may yield a more appropriate genus assignment.

Material examined. 2 specimens observed from sample 321-1337A-2H-3, 76–79cm (Late Pleistocene).

Range. Late Pleistocene in the EEP, see 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 2. Relative abundance of specimens and taxa belonging to Plagiacanthoidea and Lophophaenidae per sample, from IODP Site U1337 in the EEP over the last ~10 Ma. The relative percentages of total taxa are represented by the blue lines and the red lines represent the percentages of total specimens (triangles = Plagiacanthoidea; circles = Lophophaenidae). The Plagiacanthoidea was among the most abundant and speciose of radiolarian groups encountered in Trubovitz et al. (2020), with at least 10% of the specimens and 20% of the taxonomic richness in every sample. Within the Plagiacanthoidea, lophophaenids consistently made up the majority of specimens (~67%) and taxa (~61%). Data are from Trubovitz et al. (2020).