Lophophaena, Ehrenberg, 1847 emend. Petrushevskaya, 1971

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 : 69-70

Lophophaena ? sp. C

Plate 23, Figs. 3A – 5B .

unknown plagonid group C sp 5, Trubovitz et al., 2020, supplementary data 7.

Remarks. This species has a pointed cephalis with at least one spine protruding from the top. Other, smaller spines are occasionally preserved on sides of cephalis. This species resembles L. nadezdae Petrushevskaya (Pl. 23, Figs. 1A – 2C ) except that the cephalis comes to a point at the top rather than flattening into a rectangular shape. It also differs from L. nadezdae and the other species in this genus in that it has a discernable axobate. Only one specimen had this character well-preserved, but some of the others hint at a broken-off axobate that was not preserved. This species has some morphological similarities to the genus Antarctissa , so the genus assignment to Lophophaena is tentative.

Material examined. 7 specimens from samples 321-1337A-12H-5, 23–26cm (Late Miocene), 321-1337A-10H-2, 91–94cm (Early Pliocene), 321-1337A-6H-3, 29–32cm (Late Pliocene), 321-1337A-5H-5, 11–14cm (Late Pliocene), 321-1337A-4H-2, 16–19cm (Middle Pleistocene), 321-1337A-3H- 2, 103–106cm (Middle Pleistocene), and 321-1337A-2H-3, 76–79cm (Late Pleistocene).

Range. Late Miocene—Pleistocene, 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 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).

FIGURE 3. Locality map of IODP Site U1337, where all samples for this study were collected. Map from Google EarthTM.

FIGURE 5. Internal skeletal structure of Amphiplecta acrostoma Haeckel, 1887.