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Alyonushka filia

Grischenko, Gordon & Melnik, 2018

GBIF:10038220

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PROFILE

Species Profile

Habitat

Marine

Characteristics

Extant

ABOUT

Descriptions(5)

Description. Colony erect, pedunculate and subcalyciform, with outwardly flaring capitulum of relatively long autozooidal peristomes in mature colonies (Fig. 21 A, B), up to maximum of c. 27 long and short peristomes in single irregular whorl; lower parts of some peristomes fused with shorter neighbors in slightly more abfrontal position. Calyx center in immature colonies bowl-like with a few relatively large peripheral alveoli. Column narrowest in middle, widening evenly to moderately broad base. Entire external skeletal surface of colony minutely and excessively prickled (Fig. 22 F – J, L). Skeletal microstructure of generally irregular angular imbricated crystallites (Fig. 22 E). Proximal half of column may become thickened by development of layers of overlapping flattened, cushion-like alveoli / kenozooid-like chambers. Autozooidal peristomes with staggered barbed ridges (Figs 21, 22 A – D). Pores simple, small, sparse (Fig. 22 D). Apertures rounded, the rims bearing up to 10 evenly spaced projections of peristomial ridges (Fig. 22 A, C – E, I, K). Interior of peristomes with simple scattered spinules (Fig. 22 K); these longer and more acicular in openings of developing zooids (Fig. 22 F). Gonozooids 1 – 2 per mature colony (Figs 21 A – C, 22 A), occupying calyx center, large, convex; surface highly irregular owing to rims of adjacent alveoli bearing irregularly oriented thorn-like processes (Figs 21 C, 22 B), all minutely prickled (Fig. 22 G). Incubation-chamber floor continuous (Figs 21 E, 52 C). Ooeciostome (s) relatively broad and low, ooeciopore subrounded, very little elevated, thin-walled; inner face with sparse granulation (Fig. 22 J, L). CT scans show narrow shelf within ooeciostome at inner entrance to gonozooid (Fig. 52 C). Ancestrula not seen in isolation, but erect judging from smallest (four-zooid) colony stages seen (Fig. 23 A – J); CT scans confirm protoecial dome with erect peristome arising from its center, with first daughter zooid also produced from dome adjacent to it (Fig. 52 D, E). Low trabeculae form in center of developing colony to support continuing elevation and expansion, with extrazooidal alveolar spaces between trabeculae and kenozooid-like chambers supporting stem. Measurements (mm). Holotype, ZIRAS 1 / 50710 (Fig. 21 A, B): Colony height 3.20; capitulum 2.44 × 1.86; attachment base 1.15 × 1.03; stalk height 1.71, thickness 0.45 × 0.41 to 0.80 × 0.77; ZL 0.932 – 1.238 (1.062 ± 0.102); PeL 0.593 – 1.055 (0.812 ± 0.138); PeD 0.151 – 0.173 (0.160 ± 0.007); ApL 0.130 – 0.154 (0.143 ± 0.009); ApW 0.103 – 0.125 (0.116 ± 0.007). Gonozooid 1 (n = 1): GZL 0.695; GZW 0.410; OsL 0.123; OsW 0.101. Gonozooid 2 (n = 1): GZL 0.780; GZW 0.558; OsL 0.130; OsW 0.116. Non-type specimen GLD 4 – 09, Stn 173 (Fig. 23 A, B): AnPeD 0.123 (n = 1).