Lophophaena rusalkae, n. sp.
Creators: name: Trubovitz, Sarah
name: Renaudie, Johan
name: Lazarus, David
name: Noble, Paula
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Chromista
Radiozoa
Polycystina
Nassellaria
Plagiacanthidae
Lophophaena
Lophophaena rusalkae

description: Lophophaena rusalkae n. sp.   
Plate 29, Figs. 1A – 6.  
urn:lsid:zoobank.org:act: ABD2BBA6-AD2F-4F87-BFE1-2489F79257E8  
 unknown plagonid group C sp 51, Trubovitz et al., 2020, supplementary data 7.   
 unknown plagonid group C sp 53 cf, Trubovitz et al., 2020, supplementary data 7.   
 Diagnosis. A small Lophophaena with many thin spines on the thumb-shaped cephalis, and a thorax with distinct shoulders that tapers toward the base.   
 Description. This species has a small, thumb-shaped cephalis that has many thin spines extending from the sides and top. The apical spine is embedded in the cephalis wall and is diminished to the point of being difficult to detect. The thorax is slightly wider than the cephalis, and reaches its widest point at the shoulders, where more thin spines extend downward. Pores on the cephalis and thorax are the same size, shape, and density. Both the cephalis and thorax show approximately the same degree of silicification. When the full skeleton is preserved, the thorax has a smooth termination at its base.   
 Remarks. This species differs from Botryopera babayagae n. sp. (Pl. 9, Figs. 1A – 8) in that it has thin conical spines on top of the cephalis, and a longer, more narrow neck area. It differs from Lophophaena cylindrica (Pl. 22, Figs. 1A – 4) and Lophophaena hispida (Pl. 22, Figs. 5–8B) in that it has a smaller, more thumb-shaped cephalis, with less of a constriction at the neck. It differs from Lophophaena nadezdae (Pl. 23, Figs. 1A – 2C) in that it has fewer spines, and the cephalis is smaller, and more rounded at the top. The top of the cephalis is never open, differentiating this species from Lophophaena variabilis (Pl. 22, Figs. 9A –11C) and Lophophaena buetschlii (Pl. 24, Figs. 1A – 2B). This species has similar overall structure to Lophophaena casperi n. sp. (Pl. 28, Figs. 1A – 9B.), but differs in its smaller size and cephalis shape (Figure 12).   
 Material examined. 33 specimens observed from samples 321-1337D-23H- 6, 134–137cm (Late Miocene), 321-1337A-18H-6, 77–80cm (Late Miocene), 321-1337A-14H-7, 39–42cm (Late Miocene), 321-1337A-12H-5, 23–26cm (Late Miocene), 321-1337A-7H- 6, 104–107cm (Early Pliocene), and 321-1337A-6H-3, 29–32cm (Late Pliocene).   
 Holotype. Pl. 29, Fig. 4; sample 321-1337A-14H-7, 39–42cm; ECO-138; N20-4.   
 Paratypes. (1) Pl. 29, figs. 5A–B; sample 321-1337A-12H-5, 23–26cm; ECO-136; X10-2. (2) Pl. 29, figs. 2A–B; sample 321-1337A-14H-7, 39–42cm; ECO-140; Z14-2. (3) Pl. 29, figs. 1A–B; sample 321-1337A-14H-7, 39–42cm; ECO-139; Y39-3. (4) Pl. 29, figs. 2A–B; sample 321-1337A-14H-7, 39–42cm; ECO-139; X7-2. (5) Pl. 29, fig. 3; sample 321-1337A-12H-5, 23–26cm; ECO-136; Z5-4. (6) Pl. 29, fig. 6; sample 321-1337A-14H-7, 39–42cm; ECO-139; O25-3. (7) [not figured] sample 321-1337A-14H-7, 39–42cm; ECO-138; C25-4.   
 Measurements. Cephalis height 34–40 (37)μm; cephalis width 25–32 (28)μm; width at neck 25–31 (28)μm; width at shoulders 36–44 (41)μm. Based on 10 specimens.   
 Etymology. Named for the malicious female water spirit in Russian folklore, the rusalka.   
 Range. Late Miocene—Pliocene, in the EEP (Table 1).
description: Published as part of Trubovitz, Sarah, Renaudie, Johan, Lazarus, David & Noble, Paula, 2022, Late Neogene Lophophaenidae (Nassellaria, Radiolaria) from the eastern equatorial Pacific, pp. 1-158 in Zootaxa 5160 (1) on pages 64-65, DOI: 10.11646/zootaxa.5160.1.1, http://zenodo.org/record/10544058