taxonID	type	description	language	source
F9048791FFC3FFD1ACD8FA9DFB76FDD7.taxon	description	Description: — Frustules cylindrical, rectangular in girdle view, connected to each other with linking spines forming long colonies (Figs 1 – 8, 22). Linking spines long, fine, attenuate, with anchor-shaped tip and irregular acute outgrowths on the side (Figs 22 – 26). Cingulum composed of numerous open girdle bands entirely perforated by very fine pores (Fig. 21). Copulae ligulate. Valvocopula broad, with fimbriate advalvar margin (Fig. 21). Mantle fairly high, 4 – 6 µm in height. Mantle striae fine, composed of small, irregularly rounded to rectangular areolae, arranged in well separated rows, spiraling in the abvalvar part of the mantle, straight in the upper part closest to the valve face / mantle junction (Figs 22 – 24). Areola density per row ca 20 in 10 μm (n = 10). Between the mantle areolae, numerous small, siliceous plaques present (Figs 22, 23). Collum, the lowermost part of the mantle, lacking areolae, narrow, reaching at most 5 % of the total mantle height (Fig. 22). Collum entirely covered by narrow, raised ribs composed of individual small silica granules (Figs 22 – 24). Valves circular, 7.0 – 12 μm in diameter (n = 20). Discus flat, entirely devoid of areolae. Only marginal areolae present (Figs 25, 27). Spines located between the marginal areolae, placed on the valve face edge (Fig. 25). Internally, very shallow Ringleiste visible (Figs 9, arrow, 28). Areolae covered by individual vela (Fig. 28).	en	Vijver, Bart Van De, Willems, Luna, Haan, Myriam De, Ballings, Petra, Pottiez, Margaux (2025): Aulacoseira westfjordensis, a new centric diatom species from Iceland (Aulacoseiraceae, Coscinodiscophyceae). Phytotaxa 712 (1): 75-80, DOI: 10.11646/phytotaxa.712.1.7, URL: https://doi.org/10.11646/phytotaxa.712.1.7
F9048791FFC3FFD1ACD8FA9DFB76FDD7.taxon	materials_examined	Type: — ICELAND. Westfjords (Vestfirðir), River at Mjóifjörður, sample W 022 (65 ° 53 ’ 11.01 ” N, 22 ° 50 ’ 56.71 ” W), coll. date 09. VI. 2023, leg. B. Van de Vijver (holotype slide BR- 4890 = Fig. 10, isotype slide 454, University of Antwerp, Belgium). PhycoBank registration: — http: // phycobank. org / 105731	en	Vijver, Bart Van De, Willems, Luna, Haan, Myriam De, Ballings, Petra, Pottiez, Margaux (2025): Aulacoseira westfjordensis, a new centric diatom species from Iceland (Aulacoseiraceae, Coscinodiscophyceae). Phytotaxa 712 (1): 75-80, DOI: 10.11646/phytotaxa.712.1.7, URL: https://doi.org/10.11646/phytotaxa.712.1.7
F9048791FFC3FFD1ACD8FA9DFB76FDD7.taxon	etymology	Etymology: — The specific epithet refers to the geographical location (Westfjords, Vestfirðir in Icelandic language) where the new species was found.	en	Vijver, Bart Van De, Willems, Luna, Haan, Myriam De, Ballings, Petra, Pottiez, Margaux (2025): Aulacoseira westfjordensis, a new centric diatom species from Iceland (Aulacoseiraceae, Coscinodiscophyceae). Phytotaxa 712 (1): 75-80, DOI: 10.11646/phytotaxa.712.1.7, URL: https://doi.org/10.11646/phytotaxa.712.1.7
F9048791FFC3FFD1ACD8FA9DFB76FDD7.taxon	biology_ecology	Ecology & associated diatom flora: — Sample W 022 was collected from submerged stone scrapings in the weakly acid river flowing into the Mjóifjörður fjord in the Westfjords in Iceland. It was dominated by several Psammothidium species, Meridion circulare (Greville 1822: 213) C. Agardh (1831: 40), Hannaea linearis (Holmboe 1899: 31) Álvarez-Blanco & S. Blanco (2013: 147), Odontidium mesodon (Ehrenberg 1839: 57) Kützing (1849: 12), Tabellaria flocculosa (Roth 1797: 192) Kützing (1844: 127), Rossithidium pusillum (Grunow in Cleve & Grunow 1880: 23) Round & Bukhtiyarova (1996: 351) and several, at present unidentified Gomphonema, Staurosira and Fragilaria species. According to Lange-Bertalot et al. (2017), most of these species are typical for nutrient-poor, slightly acid, soft-water rivers and lakes, and several of them have a boreal distribution such as H. linearis (Álvarez-Blanco & Blanco 2013). The species was observed in several other brooks and rivers in the Westfjords showing its broader distribution in this region (Willems et al. unpubl. res.). Kulikovskiy et al. (2010) most likely observed the species in a Sphagnum bog in Mongolia. Due to confusion with similar species (A. septentrionalis, A. helvetica) its actual distribution is therefore probably obscured.	en	Vijver, Bart Van De, Willems, Luna, Haan, Myriam De, Ballings, Petra, Pottiez, Margaux (2025): Aulacoseira westfjordensis, a new centric diatom species from Iceland (Aulacoseiraceae, Coscinodiscophyceae). Phytotaxa 712 (1): 75-80, DOI: 10.11646/phytotaxa.712.1.7, URL: https://doi.org/10.11646/phytotaxa.712.1.7
