Levisulculus obliquus ( Steusloff, 1895 ), 1967

Schallreuter, Roger E. L. & Hinz-Schallreuter, Ingelore C. U., 2010, Sexual dimorphism and pore systems in Ordovician ostracodes, Acta Palaeontologica Polonica 55 (4), pp. 741-760 : 750-754

Levisulculus obliquus ( Steusloff, 1895)

Figs. 3E–I, 4A, 7B.

1895 Primitia elongata Kr. var. obliqua n. v.; Steusloff 1895: 783,

pl. 58: 12. 1895 Primitia canaliculata n. sp.; Steusloff 1895: 782, pl. 58: 9. non 1897 Primitia elongata Krause var. obliqua Steusloff. ; Krause

1897: 934. 1934 Primitia (? Eurychilina ) elongata obliqua Steusloff ; Bassler and

Kellett 1934: 70, 443.

Fig. 4. Oepikellid ostracods from Palaeozoic erratic boulders. A. Levisulculus obliquus ( Steusloff, 1895) , erratic boulder G−287, GG 347−5a, female right H valve, L 1.20 mm; interior (A 1) and anterior (A 2) views. B, C. Swantina crassiconvexa sp. nov. from erratic boulder 1B1. B. Paratype, GG 33−19, right tecnomorphic valve, L 1.02 mm; lateral (B 1) and ventral (B 2) views. C. Holotype, GG 33−18, female left valve, L 1.17 mm; lateral (C 1), ventral (C 2), and anterior (C 3) views. D. Swantina pseudobliqua Schallreuter,1986 from erratic boulder Sy−208. GG 347−6, tecnomorphic left valve, L 0.93 mm; lateral view (ventral view: Fig. 6F). E, F. Swantina serrata Schallreuter, 1986 from erratic boulder Sy−208. E. GG 347−7, anterodorsally incomplete tecnomorphic right valve, L 0.67 mm (without spines); lateral view. F. Neotype, GG 347−8, female left valve, L 1.06 mm; anterior (F 1) and lateral (F 2) views. G. Swantina serrata Schallreuter, 1986 from erratic boulder G30. GG 347−9a, female right valve with borings parallel to surface, L 0.93 mm; detail of frill with the borings (G 1) and specimen in lateral view (G 2). H. Ampletochilina ? granulifera ( Sarv, 1962) from erratic boulder Sy−208. GG 347−4, left tecnomorphic valve,

L 1.09 mm; lateral view. Stereo−pairs, except of A 2, B 2, and H. Erratic boulder 1B1 of lower Upper Ordovician Backsteinkalk of Swedish origin from the

Isle of Hiddensee, Baltic Sea, all other erratic boulders are of upper Upper Ordovician Öjlemyr flint and came from the Isle of Gotland, Baltic Sea (G) and the Isle of Sylt, North Sea (Sy). Scale bars 0.3 mm.

doi:10.4202/app.2009.0056

the straight hinge line); Hm, maximal H; L, length; LD (HD), L (H) of the domicilium; LV, left valve; RV, right valve; tec, tecnomorph.

1954 Primitia elongata obliqua Steusloff, 1894 =? Platybolbina plana (Krause, 1889) ; Henningsmoen 1954: 87, 89.

1957 Platybolbina obliqua (Steusloff, 1894) ; Jaanusson 1957: 260.

1967 Levisulculus obliquus ( Steusloff, 1895) ; Schallreuter 1967: 616.

non 1979 Levisulculus obliqua (Ulrich, 1900) ( Ctenobolbina ); Ivanova 1979: 102 (= Eurybolbina ulrichi ).

1986 Levisulculus obliquus ( Steusloff, 1895) ; Schallreuter 1986: 16, pl. 1: 12.

?1992 Swantina? levis sp. n.; Sidaravičienė 1992: 243–244 (partim); pl. 36: 6.

1993 Levisulculus [ Primitia ] canaliculatus (St.) ; Schallreuter 1993: 17, table 2.

1999 Levisulculus cf. obliquus ( Steusloff, 1895) ; Schallreuter et al. 1999: pl. 1: 2.

Type material: Lectotype: Left tecnomorphic valve embedded in rock GG 114−27, designated by Herrig and Nestler 1989: 23 (see Fig. 2E ), figured by Steusloff 1895: pl. 58: 12. Catalogue of Herrig and Nestler 1989 no. 178 (not mentioned in the catalogue of Keyser and Schöning 1996). Paratypes: GG 114−26, GG 114−28, and GG 114−29, all right tecnomorphic valves ( Fig. 2F–H ).

Type locality: Neubrandenburg, Mecklenburg, ~ 53 ° 35’ N ~ 13 ° 15’ E, erratic boulder.

Type horizon: Geschiebe of “Borkholmer Kalk”.From the yellow−white dense limestone boulder Steusloff (1895: 781–783) described four further species and mentioned three more ( Table 5). Another species recovered from this boulder by Schallreuter (1972) is Rectella carinaspinata Schallreuter, 1972 . Apart from ostracodes, the boulder yielded trilobites, brachiopods, and crinoid columnals.

Diagnosis (emended).—Length at least up to 1.20 mm (holotype without velum 1.16 mm). Shape mostly moderately high, domicilium mostly rather long. Posteriorly directed velar spine at the border between centroventral and posteroventral regions. Lateral surface irregularly pustulate.

Dimensions and proportions.—See Table 6.

Remarks.— Henningsmoen (1954: 87) considered Primitia elongata obliqua to be a possible synonym of Platybolbina plana . Accordingly, Jaanusson (1957: 260) did not include P. obliqua in his new genus Levisulculus .

Fig. 5. Oepikellid ostracods from Palaeozoic erratic boulders. A–C. Ampletochilina trapezoidea Schallreuter, 1969 from erratic boulder G−287. A. GG H 347−11a, tecnomorphic right valve, L 1.36 mm; lateral (A 1) and ventral (A 2) views. B. GG 347−11b, tecnomorphc right valve, L 0.90 mm; lateral view. C. GG 347−12, female right valve, L 1.37 mm; oblique interior view. D. Ampletochilina trapezoidea Schallreuter, 1969 from erratic boulder 794. Holotype, GG 25−10,

a, female right valve, L 1.61 mm; lateral (D 1) and ventral (D 2) views. E–H. Swantina pseudobliqua Schallreuter, 1986 . E. Holotype, GG 400−3347, female left valve, L 1.14 mm; lateral (E 1) and ventral (E 2) views; erratic boulder Sy−207. F. GG 347−6, tecnomorphic left valve, L (domicilium) 0.86 mm; ventral view (lateral view: Fig. 4D); erratic boulder Sy−208. G. GG 347−10a, tecnomorphic right valve, L 0.99 mm; ventrolateral view, (lateral view: Fig. 6G); erratic boulder Sy−60. H. GG 347−13, female right valve, L 1.07 mm; lateral view; erratic boulder Sy−208. I–L. Swantina swantia ( Schallreuter, 1969) . I. GG 347−14, female left valve, L 1.23 mm; oblique ventral view; erratic boulder 1B1. J. GG 347−15, female right valve, L 1.10 mm; lateral view; erratic boulder 1B2. K. GG 347−16a, tecnomorphic right valve, L 1.10 mm; lateral (K 1) and ventral (K 2) views; erratic boulder 1B16. L. GG 347−16b, tecnomorphic left valve, L 1.02 mm; ventral view; erratic boulder 1B4. M. Swantina serrata Schallreuter, 1986 from erratic boulder Sy−208. GG 347−17, tecnomorphic left valve, L 1.04 mm; lateral (M 1) and ventral (M 2) views. Stereo−pairs, except of A 2, D 2, E 2, F, G, K 2, L, and M 2. Erratic boulders 1B1, 1B2, 1B4, and 1B16 of lower Upper Ordovician Backsteinkalk boulders of Swedish origin from the Isle of Hiddensee, Baltic Sea, all other erratic boulders are of upper Upper Ordovician Öjlemyr flint and came from the Isle of Gotland, Baltic Sea (G) and the Isle of Sylt, North Sea (Sy). Scale bars 0.3 mm.

doi:10.4202/app.2009.0056

The female valve from the Pirgu Stage (F1c) of Lithuania figured as Swantina? levis by Sidaravičienė (1992: pl. 36: 6) may belong to Levisulculus obliquus . However, the specimen is larger (1.40 mm) than the largest specimen of L. obliquus figured here (1.20 mm).

Primitia canaliculata Steusloff, 1895 ( Fig. 2I ) is based on an internal mould of a larval right valve. It co−occurs with the lectotype of Primitia obliqua and could be considered as a synonym of the latter species or as a nomen dubium.

Stratigraphic and geographic range.— Known only from glacial erratic boulders of Northern Germany and Sweden ( Isle of Gotland). Öjlemyr flint erratic boulders of the Isle of Gotland, Baltic Sea (791 [6 specimens], 794 [2], G−287 [12]) and the Isle of Sylt , North Sea (Sy−60 [3], Sy−75 [1], Sy−115; Schallreuter 1986: pl. 1: 12) .

Figures

Fig. 2. Oepikellid ostracods from Palaeozoic erratic boulders. A. Holotype of the type species of the oepikellid ostracod Levisulculus, Levisulculus lineatus Jaanusson, 1957 (UM T89), female left valve, length (L) 0.89 mm. B. Holotype of Primitia extraria Öpik, 1937 (TUG 1120−1; Kukruse Stage, Estonia), tecnomorphic right valve, L 0.88 mm. C. Holotype of Primitia troedssoni Thorslund, 1940 (UM T10), tecnomorphic right valve, L 0.79 mm. D. Holotype of Primitia granulosa Thorslund, 1940 (UM T11), tecnomorphic right valve, L 0.86 mm (Jaanusson 1957: pl. 8: 12, Öpik 1937: pl. 10: 19, Thorslund 1940: pl. 1: 16, 13). E–H. Primitia elongata obliqua Steusloff, 1895: type series, all tecnomorphic valves embedded in rock. Geschiebe (glacial erratic boulder) from Neubrandenburg. E. Lectotype GG 114−27, left valve, L 1.16 mm (without velum). F. GG 114−26, right valve, L 1.07 mm. G. GG 114−28, right valve, L 0.99 mm (without velum). H. GG 114−29, right valve, L 0.82 mm. I. Primitia canaliculata Steusloff, 1895, holotype GG 114−25, steinkern of a juvenile right valve embedded in rock, L 0.70 mm, same erratic boulder.