Psammothidium superpapilio Kopalova, Zidarova & Van de Vijver 2016, sp. nov.

• Main Authors: Kopalová, Kateřina, Zidarova, Ralitsa, Vijver, Bart Van De
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2016
• Subjects: Biodiversity; Taxonomy; Chromista; Bacillariophyta; Bacillariophyceae; Achnanthales; Achnanthidiaceae; Psammothidium; Psammothidium superpapilio; Antarc*; Antarctica; Livingston Island; South Shetland Islands
• Online Access: https://doi.org/10.5281/zenodo.3853082; http://treatment.plazi.org/id/03873C46FFC6FFE5FEDA4969A2A2FD5B

Psammothidium superpapilio Kopalová, Zidarova & Van de Vijver sp. nov. Figs 86–109 Etymology The specific epithet refers to the similarity with P. papilio and the larger valve dimensions. Type Byers Peninsula, Livingston Island, South Shetland Islands, Antarctica, sample BYM-008 (62°40′11.3″S 61°08′45.3″W) (leg. B. Van de Vijver), coll. date: 9 Jan. 2009 (holo-: slide no. BR–4439; iso-: slide PLP–295, University of Antwerp, Belgium). Description Light microscopy (Figs 86–105) Valves lanceolate to lanceolate-elliptic with convex to sometimes more straight margins gradually tapering towards the broad cuneately rounded apices. Valve dimensions (n = 40): length 15–20 µm, width 4.5–5.5 µm. Raphe valve (Figs 96–105): valves clearly convex. Axial area narrow, linear, almost not widening towards the central area. Central area forming a broad rectangular to bow-tieshaped subfascia with several (3–5) shortened striae present near the valve margins. Raphe straight with indistinct, straight proximal endings. Distal fissures not discernible in LM. Transapical striae weakly radiate near the central area, becoming more strongly radiate towards the apices, 28–30 in 10 µm. Areolae not discernible in LM. Rapheless valve (Figs 86–95): thickened marginal crest clearly visible in LM. Axial area very narrow, linear-lanceolate, clearly widening towards the central area. Pseudoraphe clearly present as a series of irregular depressions in the axial area. Central area rounded to rhombical, bordered by several shortened striae. Fascia never present. Transapical striae weakly radiate throughout becoming more strongly radiate towards the apices, 26–29 in 10 µm. Scanning electron microscopy (Figs 106–109) Raphe valve (Figs 106–107): axial area weakly raised and more heavily silicified (Fig. 106). Striae uniseriate, composed of long series of very small, rounded to rectangular areolae (Fig. 106). Number of areolae per striae diminishing towards the axial area (Fig. 106). On the valve face/margin junction, one transapically elongated ...