Lophophaena sp. E

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. E group

Plate 37, Figs. 1A – 3C .

Remarks. These three specimens almost certainly belong to different species, but as we only observed three specimens with this very distinct morphology we are placing them together in one group until more specimens are found.All three have an unusually short and widely-flared thorax with teeth, and a proportionally large cephalis. This overall morphology is similar to a specimen figured by Popofsky (1913) as Lampromitra circumtexta, Popofsky, 1913 , pl. 32, fig. 1, text-fig. 53. However, none of our specimens appear to be conspecific with Popofsky’s. One specimen observed from sample 6H3, 31–32cm (Pliocene) differs from Popofsky’s illustrated specimen in that pores on the thorax decrease significantly in size before the segment terminates in several prominent teeth. Our specimen also may have more pronounced shoulder humps, though it is difficult to tell whether this character was present on Popofsky’s specimen due to the nature of the illustration. The overall morphology, shape of the cephalis, and size dimensions are very similar to Popofsky’s specimen, however. A much smaller specimen was found in our Pleistocene EEP sample (3H 2, 103–106cm). It shares several characteristics with our Pliocene specimen, including a large, thorny cephalis with a short, wide thorax that terminates in multiple long teeth, which is a highly unusual morphology for lophophaenids. A third specimen with similar characteristics to our other two was observed in sample 10H2, 91–93cm, although we do not consider any of them to be conspecific. Until additional material is studied, we include them here as a loose species group.

Material examined. 3 specimens form samples 321-1337A-10H-2, 91–94cm (Early Pliocene), 321-1337A-6H-3, 29–32cm (Late Pliocene), and 321-1337A-3H- 2, 103–106cm (Middle Pleistocene).

Range. Pliocene– Pleistocene, EEP ( Table 1 ). Range and morphological concept is not well constrained.

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