Lophophaena decacantha ( Haeckel, 1887 ), 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 : 56

Lophophaena decacantha ( Haeckel, 1887) group sensu Takahashi, 1991

Plate 27, Figs. 1A – 2B .

Lophophaena decacantha Haeckel group, Takahashi, 1991, pl. 25, figs. 2, 8.

Lophophaena decacantha Haeckel group, Trubovitz et al., 2020, supplementary data 7.

Remarks. This species group differs from many others in Lophophaena in that the apical spine flares out from the cephalis, and is usually reinforced by skeletal buttressing where it separates from the cephalis, similar to the cephalic spine structure of Lophophaena decacantha (Haeckel) Petrushevskaya sensu stricto. However, it differs from Lophophaena decacantha ss., in that the top of the cephalis is not hyaline, the neck area is not as constricted, and there is only one major spine on the cephalis, which is more poorly developed than the four strong cephalic horns of L. decacantha . Takahashi’s group concept likely includes multiple distinct species.

Material examined. 22 specimens observed from samples 321-1337A-12H-5, 23–26cm (Late Miocene), 321- 1337A-10H-2, 91–94cm (Early Pliocene), 321-1337A-7H- 6, 104–107cm (Early Pliocene), 321-1337A-6H-3, 29– 32cm (Late Pliocene), 321-1337A-5H-5, 11–14cm (Late Pliocene), 321-1337A-4H- 6, 115–118cm (Early Pleistocene), 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. Latest Miocene—Late 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).