Cyclopsinella steinmanni ( Munier-Chalmas, 1887 )

Schlagintweit, Felix, 2020, Maastrichtian Larger Benthic Foraminifera From The Arabian Plate Sensu Lato: New Data From Somalia, Turkey, And Iran, Acta Palaeontologica Romaniae 16 (2), pp. 69-83 : 75

Cyclopsinella steinmanni ( Munier-Chalmas, 1887)

Fig. 5

1963 Cyclopsinella steinmanni (Munier-Chalmas) – Gendrot, p. 531, pl. 1, figs. 6-10, text-figs. 1-2.

1971 Cyclopsinella steinmanni (Munier-Chalmas) – Ramírez del Pozo, pl. 116, pars (upper Santonian of northern Spain).

1974b Cyclopsinella steinmanni (Munier-Chalmas) – Meriç, pl. 1, figs. 1-3 (Maastrichtian of SE Turkey).

?2019 Cyclopsinella roselli n. sp. – Villalonga et al., p. 10, fig. 10a-e (middle Campanian Terradets Limestone of NE Spain).

2018 Saudia sp. – Luger, p. 61, pl. 4, fig. 10 (Maastrichtian Auradu Fm. of Somalia)..

Remarks: This taxon, which sometimes attains an irregular-discoidal morphology in axial sections, seems to be extremely rare in the Auradu Formation of Somalia ( Fig. 5a ). Luger (2018, p. 61) did neither provide any description nor dimensional data. Measured from the illustration, the shown axial section is ~ 4 mm in diameter, ~ 0.35 mm in thickness, and consists of more than 45 annular chambers. The chamber height is continuously increasing throughout ontogeny resulting in biconcave disk-like outline in axial sections. The low magnification and poor quality of the image, however, do not allow further insights into other details such as the initial chambers. In the adult chambers, aligned central pillars (cyclopsellinid endoskeleton sensu Hottinger, 2006, p. 12) are well recognizable. This feature, and the lack of an endoskeleton in the early part of the test, is also displayed in the specimen from the Tarbur Formation shown in Figure 5b . In another specimen from the Tarbur Formation, a sporadic single, very short (= rudimentary) rafter in the marginal chamber part can be observed ( Fig. 5e ). This feature has never been observed in older (Cenomanian-Campanian) species. It is here considered as an intraspecific variation like reported from some orbitolinids (e.g., Simplorbitolina manasi Ciry & Rat ; see Schroeder, 1985). The specimens from Somalia and Iran are well comparable to the upper Santonian forms of southern France ( Gendrot, 1964) ( Fig. 5d ). From SE Turkey, C. steinmanni has been reported by Meriç (1974) from the Maastrichtian of oil drilling wells Şelmo-1 and Malabadi-1, Siirt Province. No lithostratigraphic unit has been indicated by Meriç, but it should correspond to the so-called Koçali Complex, a lithostratigraphic equivalent of the Garzan Formation (Hoşgör and Košt’ák, 2012, fig. 2).

Another species of the genus Cyclopsinella has recently been described by Villalonga et al. (2019) as C. roselli from the middle Campanian of NE Spain. However, some important taxonomic works on Cyclopsinella by Gendrot (1963), Neumann (1964), Meriç (1974b), and Cherchi (1980, 1985) have not been taken into consideration by Villalonga et al. (2019). Otherwise, a pure comparison and analysis of the therein provided data with respect to test diameter and number of chambers should have made very doubtful its creation ( Table 2). In this context, the overlapping stratigraphy, upper Santonian-Maastrichtian for C. steinmanni (see synonymy), and middle Campanian for C. roselli , is also worth mentioning. By the way, the specimens of C. roselli show an almost complete fusion of the pillars in the interior of the last chambers. The typical tendency of this particular pattern ( Hottinger, 2006, p.12) has not been mentioned in the description of C. roselli .

Zekritia (type-species Z. langhami ) described by Henson (1948) from the Cenomanian of Qatar might be a junior synonym of Cyclopsinella (see Gendrot, 1964; Fourcade et al., 1994). Z. langhami would then be a junior synonym of the Cenomanian C. neumannae Cherchi (see Cherchi, 1980, 1985). In fact, the single section shown by Henson (1948, pl. 11, fig. 7) displays the typical cyclopsinellid structure of the pillars ( Hottinger, 2006, p. 12). Loeblich and Tappan (1987, p. 715) treat Zekritia as a genus of uncertain status.

Figures

Fig. 5 Cyclopsinella steinmanni (Munier-Chalmas) from the upper Maastrichtian of Somalia (Auradu Formation: a), Iran (Tarbur Formation: b-c, e-f), and C. steinmanni from the upper Santonian of France (d). a from Luger (2018, pl. 4, fig. 10 as Saudia sp.). b-c, e-f Naghan section. Note the aligned pillars (partly fusing laterally) in b and f, and sporadic rudimentary short rafter (r) in e. d from Gendrot (1964, pl. 1, fig. 10). Abbreviations: pi = pillar, r = rafter, s = septum.