Planicirrata Nygren, 2004, gen. n.

• Main Author: Nygren, Arne
• Format: Other/Unknown Material
• Language: unknown
• Published: 2004
• Subjects: Biodiversity; Taxonomy; Animalia; Annelida; Polychaeta; Phyllodocida; Syllidae; Planicirrata; Antarctic; Elephant Island; Nygren; Antarc*
• Online Access: https://zenodo.org/record/6273226; https://doi.org/10.5281/zenodo.6273226

Planicirrata gen. n. Linnean name definition. Type species Myrianida proceraeae Hartmann­Schröder & Rosenfeldt, 1990. PhyloCode definition. No name definition provided. Apomorphies. Supported by 3 morphological apomorphies (Fig. 4): 1) cirrostyles flattened (character 15), character state change is a parallelism; 2) pharynx sinuation with several sinuations (character 39), character state change is a parallelism; 3) number of rows of muscle cells equals 41–50 (character 48), character state change is a parallelism. Etymology. Plani is latin, meaning flat. Named for its flattened cirrostyles. Planicirrata proceraeae (Hartmann­Schröder & Rosenfeldt, 1990) comb. n. (Fig. 46 A–G) Myrianida proceraeae Hartmann­Schröder & Rosenfeldt, 1990: 100 –101, figs 1–3; 1992: 104. Material examined. Antarctic: holotype, ZMH 19924, Elephant Island, 60 ° 51.3 'S, 55 ° 45.6 'W, 290 m, stones, 26 Feb 1985. Diagnosis. Procerini with flattened lanceolate cirrostyles. Description. Holotype complete, length 14 mm for 90 chaetigers, width 1.4 mm at level of proventricle. Preserved material yellowish, without colour markings; eyes reddish orange. Body shape, excluding parapodial lobes, cylindrical in transection, stout (Fig. 46 A), venter flattened. Body distinctly thicker in anterior 20 chaetigers. Ciliation not possible to assess. There is an indication of a stolon head behind chaetiger 13, with 3 minutely developing antennae (Fig. 46 B). Prostomium rounded rectangular, wider than long. Four eyes, with lenses, present in trapezoid arrangement, anterior pair larger. Eyes separated; eye spots absent. Palps small, in dorsal view projecting 1 / 5 of prostomial length (Fig. 46 A), fused. Nuchal epaulettes reaching end of tentacular segment. Antennae as well as ventral tentacular cirri and first dorsal cirri lost. Dorsal tentacular cirri reaching chaetiger 3. Alternation in direction of cirri not assessed. Dorsal cirri on anterior 10 chaetigers lost, all other cirri equal in length (Fig. 46 C), c. 1 / 8 of body width. Indistinct ...