Ammodiscus cretaceus ( Reuss, 1845 )

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 : 24-25

Ammodiscus cretaceus ( Reuss, 1845)

Figure 13.5

1845 Operculina cretacea ; Reuss, p. 35, pl. 13, figs. 64, 65.

1860 Cornuspira cretacea Reuss ; Reuss, p. 177, pl. 1, fig. 1.

1978 Ammodiscus cretaceus (Reuss) ; Krasheninnikov and Pflaumann, p. 569, pl. 2, fig. 7.

2005 Ammodiscus cretaceus (Reuss) ; Kaminski and Gradstein, p. 145, pl. 14, figs. 1-10.

2009 Ammodiscus cretaceus (Reuss) ; Kender, Kaminski, and Jones, p. 495, pl. 1, fig. 16, pl. 2, fig. 5.

Material. 10 specimens from seven samples.

Description. Test large, circular, biconcave, composed of a spherical proloculus followed by a single tubular chamber planispirally coiled. The whorls

(up to 11) increase gradually in size. Wall thin and finely agglutinated. Aperture at the end of the tubular chamber.

Distribution. Cosmopolitan taxon; known from the

Cretaceous to the late Eocene ( Kaminski and

Gradstein, 2005). Signaled from the Oligocene of the Beaufort-Mackenzie Basin ( Schröder-Adams and McNeil, 1994), and from the Miocene of the

Congo Fan ( Kender et al., 2008, 2009).

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.