Ammodiscus incertus ( d’Orbigny, 1839 )

Benedetti, A, 2017, Eocene / Oligocene deep-water agglutinated foraminifers (DWAF) assemblages from the Madonie Mountains (Sicily, Southern Italy), Palaeontologia Electronica 20 (1), pp. 1-66 : 25

Ammodiscus incertus ( d’Orbigny, 1839)

Figure 13.7-8

1839 Operculina incerta ; d’Orbigny, p. 49, pl. 6, figs. 16, 17.

?1884 Ammodiscus incertus d’Orbigny ; Brady, p. 370, pl. 38, fig. 1-3.

2004 Ammodiscus incertus d’Orbigny ; Govindan, p. 225, pl. 4, figs. 17, 19.

Material. Four specimens from four samples.

Description. Test discoidal commonly biconcave, composed of a single tubular chamber.

Remarks. Ammodiscus incertus differs from A. cretaceus ( Reuss, 1845) in having a constant height of the whorls, smaller size, and a typical biconvex test.

Figures

FIGURE 13. Scanning electron micrographs of Psammosphaeridae (1-4) and Ammodiscidae (5-27) from the Caltavuturo Formation cropping out at Portella Colla. 1, Psammosphaera cf. laevigata White, 1928, PCs0. 2, Psammosphaera sp. 1, PC13. 3, Psammosphaera sp. 2, PC060615. 4, Psammosphaera sp. 3, PC060625. 5, Ammodiscus cretaceus (Reuss, 1845), PC22. 6, Hyperammina sp., PC060625. 7-8, Ammodiscus incertus (d’Orbigny, 1839), PC060603 (7) and PC13 (8). 9-11, Ammodiscus tenuisimus (Gümbel, 1862), PC22 (9), PC060615 (10) and PC060615 (11). 12-13, Ammodiscus latus Grzybowski, 1898, PC11 (12) and PC11 (13). 14, Ammodiscus peruvianus Berry, 1928, PC060617. 15-16, Ammodiscus cf. latus Grzybowski, 1898, PC11. 17, Ammodiscus sp. 1, PC11. 18, Ammodiscus sp. 2, PC15. 19, Ammodiscus sp. 3, PC060603. 20, Annectina biedai Gradstein and Kaminski, 1997, PC060618. 21, Annectina cf. grzybowski (Jurkiewicz, 1960), PC060617. 22, Glomospira sp. 2, PC15. 23, Glomospira sp. 1, PC11. 24, Glomospira sp. 3, PC13. 25-26. Glomospira serpens (Grzybowski, 1898), PC060617 (25) and PC060618 (26). 27, Glomospira irregularis (Grzybowski, 1898), PC060618. Scale bar equals 0.5 mm.