Vaginulina legumen ( Linnaeus, 1758 )

Bergh, Eugene W. & Compton, John S., 2022, Taxonomy of Middle Miocene foraminifera from the northern Namibian continental shelf, Zootaxa 5091 (1), pp. 1-55 : 20

Vaginulina legumen ( Linnaeus, 1758)

Pl. 4, figs. 2–3

Nautilus legumen Linnaeus, 1758, p.711 .

Vaginulina badenensis d’Orbigny, 1846, p. 65 , pl. 3, figs. 6–8; Göes, 1894, p. 66, pl. 12, figs. 662–663; Papp & Schmid, 1985, p. 36, pl. 20, figs. 6–11.

Vaginulina legumen Brady, 1884, p. 580 , pl. 66, figs. 13–15; Bagg, 1912, p. 63, pl. XVIII, fig. 6–7; Sandidge, 1932, p. 355, pl. XXXI, fig. 15; Loeblich & Tappan, 1988, pl. 454, figs. 15–17.

Description: The test wall is calcareous and perforate. The test is large, elongate, compressed, uniserial and lenticular in cross-section. The initial end may be with or without a spine. The sutures are straight, slightly thickened and near horisontal. The aperture is pronounced, terminal and radiate.

Remarks: The relative abundance is generally low, comprising trace components (<1%) in some of the samples of core 2670. The length of the figured specimen in Sandidge (1932) is 0.7 mm. The tests in this study are larger than those in Sandidge (1932), measuring up to 0.4 mm in cross section and 2 mm in length.

There are variations in the tests presented in the synonymies of Vaginulina legumen in its length, curvature and breadth, in relation to its length. For example, the tests of V. badenensis figured in Göes (1894) appear to be more curved with the terminal end broader than the initial chambers. The figured specimens in Göes (1894) are also broader than those in d’Orbigny (1846). V. badenensis has been synonymised with V. legumen . The tests from this study closely resembles that of Papp and Schmid (1985) from the Vienna Basin. The figured test from this study (pl. 4, fig. 2) appears to be smoother, with near horisontal striae that are not that apparent in electron microscopy, but may have been worn away. Other specimens also exhibited near horisontal striae.

Life strategy: Vaginulina legumen is infaunal and adapted to suboxic conditions ( Pezelj et al., 2013 and references therein).

Global stratigraphic range: This species is recorded to occur from the Triassic to Recent ( Bagg, 1912; Sandidge, 1932).

Regional occurrence: Vaginulina legumen occurs in middle Miocene sediments on the Namibian outer continental shelf, south of the Kunene River mouth (this study).