Lophophaena sp. F

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 : 70

Lophophaena sp. F

Plate 38, Figs. 1A – 2B .

unknown plagonid group C sp 29, Trubovitz et al. 2020, supplementary data 7.

Remarks. This species is notable for its smooth, thumb-shaped cephalis, with relatively large pores and no prominent spines. The thorax is wider than cephalis, and no thoracic spines are present. Due to a lack of characters, this species is difficult to distinguish from broken specimens of similar taxa that do have numerous spines, such as Lophophaena nadezdae (Pl. 23, Figs. 1A – 2C ).

Material examined. Over 300 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), 321-1337A-2H-3, 76–79cm (Late Pleistocene), and 321-1337D-1H-1, 0–3cm (Recent).

Range. Latest Miocene—Recent, 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).