Lophophaena sp. M

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 : 72

Lophophaena sp. M

Plate 21, Figs. 6A–C .

Remarks. Only a single specimen of this unusual species was observed in our material, but it was so distinct that we chose to illustrate it here for completeness. The shape of the cephalis and bulge at the neck area closely resemble the structure of Lophophaena amictoria (Pl. 21, Figs. 1A – 3B ), but this species has an undulating thorax with much stronger feet and is more than twice its size. The curved, billowing nature of the thorax is similar to Lophophaena undulatum (Pl. 21, Figs. 4–5 ), but this species differs in its significantly larger size, larger and better developed cephalis, and more elongated neck area with prominent bulge on the dorsal side. L. undulatum also lacks the feet of Lophophaena sp. M and L. amictoria , although some specimens do develop long ribs from the dorsal and lateral spines that run partway down the thorax. This species appears to be distinct yet have some relationship to the previously-mentioned lophophaenid taxa; more material must be examined before it can be formally described.

Material examined. 1 specimen from sample 321-1337D-23H- 6, 134–137cm (Late Miocene).

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

FIGURE 4. Examples of specimen measurements discussed in the Systematic Paleontology section of this study.

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

FIGURE 6. Internal skeletal structure of Arachnocorallium calvata (Haeckel, 1887) Petrushevskaya, 1971.