Dentalina mutabilis ( Costa, 1855 )

Guðmundsson, Guðmundur, Cedhagen, Tomas & Andersen, Tom, 2022, Taxonomy and distribution of recent species of the subfamily Nodosariinae (Foraminifera) in Icelandic waters, European Journal of Taxonomy 824 (1), pp. 1-74 : 29-32

Dentalina mutabilis ( Costa, 1855)

Fig. 7

Nodosaria mutabilis Costa, 1855: 134 , pl. 1 figs 1a, c, 2a, c.

Nodosaria flintii Cushman, 1923: 85 , pl. 14 fig. 1.

Dentalina flintii – Jones 1994: 76, pl. 64 figs 20–22. — Eiland & Guðmundsson 2004: 198, pl. 1, fig. o, pl. 2 fig. a.

Dentalina mutabilis – Hayward et al. 2012: 237, pl. 39 figs 19–21.

non Nodosaria obliqua ( Linnaeus, 1758) – Goës 1894 (part): 70, pl. 12 figs 691–692 (only). — Cushman 1913: 59, pl. 25 fig. 5.

Material examined

ICELANDIC WATERS • 1; 63.2544° N, 26.4925° W; detr. sledge (Sneli); depth 1200 m; 4.09°C; 34.94 ppt; 5 Sep. 1992; BIOICE 2256 ; IINH 14647 • 40; 63.2503° N, 26.4872° W; RP sledge; depth 1209 m; 4.09°C; 34.94 ppt; 5 Sep. 1992; BIOICE 2257 ; IINH 14648 • 1; 62.4739° N, 22.6733° W; RP sledge; depth 1203 m; 3.91°C; 34.95 ppt; 9 Sep. 1992; BIOICE 2293 ; IINH 14634 • 1; 63.0619° N, 22.6756° W; detr. sledge (Sneli); depth 601 m; 6.75°C; 35.1 ppt; 10 Sep. 1992; BIOICE 2302 ; IINH 14635 • 1; 63.0744° N, 22.6894° W; RP sledge; depth 600 m; 6.75°C; 35.1 ppt; 10 Sep. 1992; BIOICE 2303 ; IINH 14649 • 2; 63.0583° N, 21.8333° W; RP sledge; depth 838 m; 5.49°C; 35.03 ppt; 1 Jul. 1993; BIOICE 2403 ; IINH 39171 • 3; 63.0417° N, 21.8556° W; detr. sledge (Sneli); depth 802 m; 5.49°C; 35.03 ppt; 1 Jul. 1993; BIOICE 2404 ; IINH 39178 • 1; 62.8667° N, 21.7361° W; RP sledge; depth 1074 m; 4°C; 34.97 ppt; 2 Jul. 1993; BIOICE 2410 ; IINH 39177 • 1; 62.7572° N, 21.5547° W; detr. sledge (Sneli); depth 1170 m; 4.17°C; 34.98 ppt; 2 Jul. 1993; BIOICE 2412 ; IINH 14650 • 3; 62.7556° N, 21.5667° W; RP sledge; depth 1171 m; 4.17°C; 34.98 ppt; 2 Jul. 1993; BIOICE 2413 ; IINH 14651 • 1; 63.0083° N, 21.0211° W; detr. sledge (Sneli); depth 784 m; 5.36°C; 35.02 ppt; 2 Jul. 1993; BIOICE 2414 ; IINH 39176 • 1; 63.005° N, 21.015° W; RP sledge; depth 819 m; 5.36°C; 35.02 ppt; 2 Jul. 1993; BIOICE 2415 ; IINH 39175 • 3; 63.0689° N, 19.8592° W; detr. sledge (Sneli); depth 1207 m; 4.45°C; 34.99 ppt; 3 Jul. 1993; BIOICE 2431 ; IINH 39174 • 2; 63.1233° N, 21.6119° W; detr. sledge (Sneli); depth 647 m; 6.09°C; 35.06 ppt; 5 Jul. 1993; BIOICE 2471 ; IINH 39173 • 2; 63.0722° N, 21.5917° W; RP sledge; depth 842 m; 5.54°C; 35.03 ppt; 5 Jul. 1993; BIOICE 2475 ; IINH 39172 • 2; 64.4361° N, 28.2389° W; detr. sledge (Sneli); depth 1162 m; 3.72°C; 34.92 ppt; 31 Aug. 1994; BIOICE 2691 ; IINH 14652 • 4; 64.1722° N, 27.7194° W; RP sledge; depth 1042 m; 4.2°C; 34.93 ppt; 2 Sep. 1994; BIOICE 2697 ; IINH 14653 • 1; 64.0972° N, 27.8361° W; RP sledge; depth 1121 m; 3.84°C; 34.92 ppt; 2 Sep. 1994; BIOICE 2701 ; IINH 14637 • 4; 63.8472° N, 27.7222° W; RP sledge; depth 1295 m; 3.8°C; 34.92 ppt; 2 Sep. 1994; BIOICE 2704 ; IINH 14654 • 5; 63.9389° N, 28.275° W; detr. sledge (Sneli); depth 1406 m; 3.71°C; 34.91 ppt; 3 Sep. 1994; BIOICE 2706 ; IINH 14638 • 7; 63.925° N, 28.2889° W; RP sledge; depth 1407 m; 3.71°C; 34.91 ppt; 3 Sep. 1994; BIOICE 2707 ; IINH 14639 • 27; 64.7278° N, 30.125° W; detr. sledge (Sneli); depth 2170 m; 3.13°C; 34.9 ppt; 3 Sep. 1994; BIOICE 2708 ; IINH 14665 • 1; 64.3861° N, 27.3194° W; detr. sledge (Sneli); depth 711 m; 6°C; 35.05 ppt; 7 Sep. 1994; BIOICE 2726 ; IINH 14656 • 1; 63.0944° N, 17.3528° W; RP sledge; depth 1085 m; 4.48°C; 35.01 ppt; 27 Aug. 1995; BIOICE 2844 ; IINH 39220 • 3; 62.3472° N, 16.9917° W; RP sledge; depth 2074 m; 2.34°C; 34.96 ppt; 29 Aug. 1995; BIOICE 2856 ; IINH 14657 • 3; 61.8394° N, 16.8906° W; RP sledge; depth 2270 m; 2.37°C; 34.95 ppt; 29 Aug. 1995; BIOICE 2859 ; IINH 14658 • 6; 61.7286° N, 16.9633° W; RP sledge; depth 2295 m; 2.6°C; 34.96 ppt; 30 Aug. 1995; BIOICE 2860 ; IINH 14659 • 2; 61.1717° N, 18.0492° W; RP sledge; depth 2400 m; 2.07°C; 34.95 ppt; 30 Aug. 1995; BIOICE 2863 ; IINH 14660 • 1; 62.0725° N, 20.5986° W; RP sledge; depth 1681 m; 2.67°C; 34.96 ppt; 31 Aug. 1995; BIOICE 2864 ; IINH 39219 • 2; 64.5767° N, 27.6106° W; detr. sledge (Sneli); depth 775 m; 6.05°C; 35.03 ppt; 22 Aug. 1996; BIOICE 2876 ; IINH 14661 • 1; 64.5878° N, 27.6167° W; RP sledge; depth 776 m; 6.05°C; 35.03 ppt; 23 Aug. 1996; BIOICE 2877 ; IINH 14662 • 1; 64.5781° N, 27.6206° W; Agassiz trawl; depth 779 m; 6.05°C; 35.03 ppt; 23 Aug. 1996; BIOICE 2878 ; IINH 14663 • 2; 65.3908° N, 28.3575° W; RP sledge; depth 1057 m; 4.78°C; 34.98 ppt; 24 Aug. 1996; BIOICE 2904 ; IINH 14899 • 1; 65.2764° N, 28.8433° W; detr. sledge (Sneli); depth 1311 m; 3.96°C; 34.94 ppt; 25 Aug. 1996; BIOICE 2907 ; IINH 39876 • 9; 65.2669° N, 28.8375° W; RP sledge; depth 1300 m; 3.96°C; 34.94 ppt; 25 Aug. 1996; BIOICE 2909 ; IINH 39877 • 6; 65.1889° N, 29.0747° W; detr. sledge (Sneli); depth 1467 m; 3.9°C; 34.94 ppt; 25 Aug. 1996; BIOICE 2911 ; IINH 39878 • 8; 65.1836° N, 29.0717° W; RP sledge; depth 1456 m; 3.9°C; 34.94 ppt; 25 Aug. 1996; BIOICE 2912 ; IINH 39879 • 3; 64.91° N, 29.9869° W; detr. sledge (Sneli); depth 2005 m; 3.21°C; 34.88 ppt; 25 Aug. 1996; BIOICE 2914 ; IINH 14897 • 2; 65.2158° N, 29.2486° W; detr. sledge (Sneli); depth 1539 m; 3.22°C; 34.93 ppt; 26 Aug. 1996; BIOICE 2918 ; IINH 14893 • 1; 62.8708° N, 14.7006° W; RP sledge; depth 1729 m; 2.51°C; 34.96 ppt; 11 Jul. 1997; BIOICE 3067 ; IINH 14640 • 1; 62.3008° N, 15.3333° W; RP sledge; depth 2067 m; 3.19°C; 34.96 ppt; 12 Jul. 1997; BIOICE 3071 ; IINH 14641 • 3; 61.9014° N, 15.1375° W; RP sledge; depth 2082 m; 2.83°C; 34.97 ppt; 12 Jul. 1997; BIOICE 3072 ; IINH 39262 • 2; 61.9075° N, 15.1547° W; detr. sledge (Sneli); depth 2085 m; 2.83°C; 34.97 ppt; 12 Jul. 1997; BIOICE 3074 ; IINH 39260 • 4; 62.0075° N, 15.9836° W; detr. sledge (Sneli); depth 2191 m; 3.07°C; 34.97 ppt; 13 Jul. 1997; BIOICE 3076 ; IINH 39261 • 4; 62.6189° N, 23.3719° W; RP sledge; depth 1250 m; 3.61°C; 34.99 ppt; 25 Jul. 2000; BIOICE 3161 ; IINH 39271 • 2; 62.6197° N, 23.3669° W; detr. sledge (Sneli); depth 1250 m; 3.61°C; 34.99 ppt; 25 Jul. 2000; BIOICE 3162 ; IINH 39263 • 6; 61.7167° N, 22.9639° W; RP sledge; depth 1741 m; 2.79°C; 34.99 ppt; 26 Jul. 2000; BIOICE 3164 ; IINH 14642 • 4; 60.9264° N, 22.7897° W; detr. sledge (Sneli); depth 1898 m; 2.98°C; 34.99 ppt; 26 Jul. 2000; BIOICE 3166 ; IINH 39264 • 6; 60.9244° N, 22.7906° W; RP sledge; depth 1897 m; 2.98°C; 34.99 ppt; 26 Jul. 2000; BIOICE 3167 ; IINH 39265 • 1; 60.7586° N, 23.72° W; RP sledge; depth 1951 m; unknown; unknown; 29 Jul. 2000; BIOICE 3177 ; IINH 39266 • 3; 60.8906° N, 26.8033° W; RP sledge; depth 1543 m; 3.53°C; 34.98 ppt; 30 Jul. 2000; BIOICE 3181 ; IINH 14643 • 1; 61.2403° N, 27.9272° W; Triangle dredge; depth 1005 m; 4.6°C; 34.97 ppt; 31 Jul. 2000; BIOICE 3183 ; IINH 39267 • 4; 62.15° N, 27.0172° W; Triangle dredge; depth 1325 m; 3.99°C; 34.96 ppt; 1 Aug. 2000; BIOICE 3186 ; IINH 39268 • 14; 62.1511° N, 27.0206° W; RP sledge; depth 1327 m; 3.99°C; 34.96 ppt; 1 Aug. 2000; BIOICE 3187 ; IINH 14644 • 5; 62.1542° N, 27.0089° W; Agassiz trawl; depth 1339 m; 3.99°C; 34.96 ppt; 1Aug. 2000; BIOICE 3188 ; IINH 39269 • 6; 62.1508° N, 26.6381° W; Agassiz trawl; depth 950 m; 5.21°C; 35.01 ppt; 1 Aug. 2000; BIOICE 3189 ; IINH 39270 • 2; 62.5306° N, 19.6639° W; RP sledge; depth 1682 m; 3.3°C; 34.99 ppt; 13 Sep. 2001; BIOICE 3263 ; IINH 39272 • 1; 62.4222° N, 19.8167° W; RP sledge; depth 1780 m; 2.95°C; 34.98 ppt; 13 Sep. 2001; BIOICE 3264 ; IINH 14645 • 4; 62.8972° N, 15.9333° W; RP sledge; depth 1692 m; 2.85°C; 35 ppt; 16 Sep. 2001; BIOICE 3280 ; IINH 39273 • 2; 62.8° N, 16.2556° W; RP sledge; depth 1813 m; 2.54°C; 34.99 ppt; 16 Sep. 2001; BIOICE 3282 ; IINH 14646 • 1; 63.0083° N, 20.5083° W; detr. sledge (Sneli); depth 814 m; 5.82°C; 35.1 ppt; 31 Aug. 2002; BIOICE 3500 ; IINH 39300 • 1; 63.0067° N, 20.5069° W; RP sledge; depth 829 m; 5.82°C; 35.1 ppt; 31 Aug. 2002; BIOICE 3501 ; IINH 39299 • 1; 62.0294° N, 19.8208° W; RP sledge; depth 1733 m; 3.09°C; 34.99 ppt; 2 Sep. 2002; BIOICE 3504 ; IINH 39298 • 14; 62.0444° N, 19.6531° W; RP sledge; depth 1678 m; 2.7°C; 34.99 ppt; 3 Sep. 2002; BIOICE 3509 ; IINH 39297 • 1; 62.2711° N, 17.5489° W; RP sledge; depth 1960 m; 2.7°C; 34.99 ppt; 5 Sep. 2002; BIOICE 3519 ; IINH 39296 • 1; 61.6642° N, 13.9181° W; RP sledge; depth 1640 m; 2.86°C; 34.95 ppt; 11 Sep. 2002; BIOICE 3543 ; IINH 39295 • 5; 62.9836° N, 18.1517° W; detr. sledge (Sneli); depth 1232 m; unknown; unknown; 12 Sep. 2002; BIOICE 3546 ; IINH 39294 • 1; 62.9844° N, 18.1564° W; RP sledge; depth 1233 m; unknown; unknown; 12 Sep. 2002; BIOICE 3547 ; IINH 39293 • 5; 63.7197° N, 29.1767° W; RP sledge; depth 1819 m; 3.24°C; 34.92 ppt; 4 Sep. 2003; BIOICE 3570 ; IINH 39291 • 6; 63.5061° N, 29.6444° W; RP sledge; depth 2233 m; 3.14°C; 34.92 ppt; 5 Sep. 2003; BIOICE 3571 ; IINH 39290 • 9; 63.3803° N, 29.9236° W; RP sledge; depth 2359 m; 3.06°C; 34.92 ppt; 5 Sep. 2003; BIOICE 3573 ; IINH 39301 • 2; 63.2947° N, 28.5669° W; detr. sledge (Sneli); depth 1744 m; 3.7°C; 34.95 ppt; 6 Sep. 2003; BIOICE 3575 ; IINH 39289 • 6; 63.0847° N, 28.4428° W; detr. sledge (Sneli); depth 1796 m; 3.42°C; 34.93 ppt; 6 Sep. 2003; BIOICE 3578 ; IINH 39288 • 3; 63.0783° N, 28.4442° W; RP sledge; depth 1796 m; 3.42°C; 34.93 ppt; 6 Sep. 2003; BIOICE 3579 ; IINH 39287 • 1; 62.385° N, 28.2881° W; detr. sledge (Sneli); depth 1548 m; 3.77°C; 34.95 ppt; 7 Sep. 2003; BIOICE 3585 ; IINH 39292 • 3; 62.3875° N, 28.2919° W; RP sledge; depth 1558 m; 3.77°C; 34.95 ppt; 7 Sep. 2003; BIOICE 3586 ; IINH 39286 • 5; 61.8019° N, 27.0386° W; detr. sledge (Sneli); depth 880 m; 6.09°C; 35.08 ppt; 9 Sep. 2003; BIOICE 3591 ; IINH 39285 • 2; 61.8044° N, 27.0328° W; RP sledge; depth 888 m; 6.09°C; 35.08 ppt; 9 Sep. 2003; BIOICE 3592 ; IINH 39284 • 3; 61.835° N, 26.1589° W; detr. sledge (Sneli); depth 906 m; 5.52°C; 35.07 ppt; 10 Sep. 2003; BIOICE 3594 ; IINH 39283 • 4; 61.8328° N, 26.1769° W; RP sledge; depth 916 m; 5.52°C; 35.07 ppt; 10 Sep. 2003; BIOICE 3595 ; IINH 39282 • 7; 62.2936° N, 25.6328° W; RP sledge; depth 769 m; 6.5°C; 35.12 ppt; 10 Sep. 2003; BIOICE 3598 ; IINH 39281

Description

Test shape elongate, cylindrical, usually straight, sometimes only slightly curved, somewhat nodular near the apertural end; tapering to a pointed initial end. Length of test commonly 4–5 mm, the largest 7 mm; test width 0.3–0.4 mm. Chambers sub-globular, rectilinearly arranged, number of chambers 8–14, or up to 16. Sutures horizontal. Aperture radial, central and protruding, with up to 14 tines that are symmetrically arranged and fused in the center. Initial end with relatively long spine; conspicuous longitudinal costae run in nearly straight lines along the whole length of the test and are fused with the base of the apertural tines ( Fig. 7D–E ); the costae divide or fuse as the diameter of the test changes. Secondary surface laminations cover the whole test (ortho-lamellar). Wall thick and finely perforated.

Remarks

All the 322 examined specimens of this species had a rectilinear chamber arrangement in the initial part. Diameter of proloculus falls usually within the range of 0.10–0.15 mm, but in few specimens the diameter reaches 0.40 mm. Robust specimens of D. mutabilis bear some superficial resemblance to exceptionally slender individuals of D. obliqua . Nevertheless, D. mutabilis differs from D. obliqua in having a central aperture and the surface costae run in direct continuation of the apertural tines ( Fig. 7E ), and nearly parallel to the axis of the test, whereas the costae are slightly twisted in D. obliqua ( Fig. 6A–B ).

Figures

Fig. 7. Dentalina mutabilis (Costa, 1855). A. Megalosphere (BIOICE 3501, IINH 39299), side view. B. Megalosphere (BIOICE 3598, IINH 39281), variant with exceptionally large proloculus. C–E. Megalosphere (BIOICE 3280, IINH 39273), side view (C), aperture (D) and aperture (E) of the same specimen stained with indigo blue. Light source combination of incident light and dark field. Scale bars = 0.25 mm.

Fig. 6. Dentalina obliqua (Linnaeus, 1758). A, D. Megalosphere (BIOICE 3104, IINH 39227), side view (A) and aperture (D). B–C. Microsphere (BIOICE 2308, IINH 14759), side view (B) and details of the initial spire (C), where outer wall has been etched with acid and stained with indigo blue; diameter of proloculus <0.02 mm. Light source combination of incident light and dark field. Scale bars = 0.25 mm.