Amphiplecta cylindrocephala? Dumitrica, 1973

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 : 14

Amphiplecta cylindrocephala? Dumitrica, 1973

Plate 1, Figs. 3A – 4C .

? Amphiplecta cylindrocephala n. sp., Dumitrica, 1973, p. 836, pl. 24, figs. 4–5.

non Amphiplecta cylindrocephala Dumitrica, Benson, 1983 , pl. 8, fig. 5.

Remarks. This species is very close to Amphiplecta acrostoma Haeckel, 1887 , but according to Dumitrica (1973), it differs in that it has a “very long cephalis, less spiny shell, and non-denticulate spines.” This species is rare, and only two Quaternary specimens were illustrated by Dumitrica (1973), so it is difficult to know the true variability of this species. In our material we encountered two specimens with an unusually long cephalis, suggestive of Amphiplecta cylindrocephala Dumitrica , but one specimen differed in that it had a slight pinch in the cephalis outline toward the top. Thus, we questionably place these specimens in Amphiplecta cylindrocephala Dumitrica. Other than the two illustrations by Dumitrica (1973), we are only aware of one other illustration of Amphiplecta cylindrocephala by Benson (1983). This specimen appears to be within the range of Amphiplecta acrostoma Haeckel , so we do not consider it to be synonymous with our Amphiplecta cylindrocephala ? specimens.

Range. Early Pliocene in the EEP ( Table 1 ).

Figures

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.