Dicyclina qatarensis Henson, 1948b

Dicyclina qatarensis Henson, 1948b View in CoL

Figure 23 View Fig

T 1948b Dicyclina qatarensis n. sp. Henson, p. 622, pl. XIV, fig. 8; Cenomanian, Qatar.

Non 1961 Dicyclina cf. qatarensis – Hamaoui, pl. 1, figs. 2-6; Cenomanian, Israel [?= D. schlumbergeri ].

1998 Dicyclina qatarensis – Whittaker et al., p. 31, pl. 48, figs. 5-7; Cenomanian, Palestine / Israel & Qatar.

2008 Dicyclina qatarensis – BouDagher-Fadel, pl. 5.3, figs. 8-9; Cenomanian, Qatar.

? 2008 Cuneolina sp. – Ahmadi et al., pl. 2, fig. 3; Cenomanian, Iranian Zagros.

2009 Dicyclina sampoi Cherchi & Schroeder – Ismail et al. , p. 402, pl. 2, figs. 3, 5, 9 (not 1-2, 4, 6-8, 10-11); late Cenomanian, Egypt.

2013 Dicyclina qatarensis – Ghanem & Kuss, fig. 14 (20, 48-50); late Cenomanian, Syria.

? 2014 Dicyclina schlumbergeri – Afghah & Fadaei, fig. 7(g); early Cenomanian, Iranian Zagros [fragment illustrated with a high density of radial partitions; precision of age doubtful].

2018 Dicyclina qatarensis – BouDagher-Fadel, pl. 5.11, figs. 1-3; pl. 5.12, figs. 8-9; Cenomanian, Qatar.

2018 Dicyclina qatarensis – Omidi et al., pl. 2, fig. 10; Turonian [?], Iranian Zagros.

2019 Dicyclina schlumbergeri Munier-Chalmas – Alloul, fig. III.9C; Cenomanian, southwest Algeria.

? 2023 Dicyclina schlumbergeri – Al-Salihi & Ibrahim, pl. 3, fig. F; middle – late Cenomanian, southern Iraq.

Reference Images: Whittaker et al. (1998) pl. 48, figs. 5-7.

Taxonomy/Identity: The limited illustrated records and the poor-quality type material provide challenges for firm identity of this species. The original type material of Henson (1948b) shows no embryonic chambers and only a limited number of sections (see also Whittaker et al., 1998). Even subsequent illustrations (see synonymy list above) provide only limited additional observations. Cherchi & Schroeder (1990b) regarded it as an “… unrecognisable species ”. Nevertheless, D. qatarensis appears distinguishable at least from D. schlumbergeri and even D. simplex and D. sampoi in having a characteristically very large number (c. 100/quadrant) of densely-packed radial partitions (“beams”) and chamberlets. It is possible that D. qatarensis is a microspheric form of another species of Dicyclina , probably D. sampoi given that D. schlumbergeri appears to be absent from the Cenomanian of Arabia (although is present in younger strata). However, that is impossible to prove without access to populations in which both “taxa” are present. Herein, we retain the use of the name D. qatarensis for specimens of Dicyclina that have distinctive densely packed radial partitions and chamberlets – however, see for example some illustrations of D. sampoi by Ismail et al. (2009) and Figure 24 below.

Hamaoui (1961) stated that his illustrated records of D. cf. qatarensis (pl. 7, figs. 2-6 therein) “… strongly resemble Dicyclina qatarensis …” (p. 13). However, we believe the partial subequatorial oblique section of Hamaoui (1961: pl. 7, fig. 2) does not show the characteristically densely-packed radial partitions (c. 100/quadrant) typical of D. qatarensis that it purports to, and that the transverse section (pl. 7, fig. 3) shows chambers very similar to those of D. schlumbergeri (see Figure 21 View Fig b-c herein). If correct, this would be the only record of D. schlumbergeri in the Cenomanian from outside Mexico, but on the meagre evidence available, must be regarded as doubtful.

D. qatarensis is sometimes erroneously recorded as D. qatarica (e.g., El-Naggar & Al-Rifaiy, 1972, 1973; Al-Salihi & Ibrahim, 2023 and also by Hamoui, 1961 (p. 7), in what must be a lapsus calami).

Confident Stratigraphic Range: middle – late Cenomanian.

Uncertain Stratigraphic Range: Turonian.

The types from Qatar ( Henson, 1948b) are almost certainly Cenomanian (association with Praealveolina reported by Le Blanc, 2015). Other illustrated records of this species are from the middle – late Cenomanian or undifferentiated Cenomanian. The exception is that of Omidi et al. (2018) that is said to be from the Turonian part of the Sarvak Formation of the Iranian Zagros, although proof of this age is not compelling from the data presented. The early Cenomanian record of Afghah & Fig. 24. Comparison between features of D. qatarensis (a-c. Whittaker et al., 1998; d. Henson, 1948b; e. BouDagher-Fadel, 2018), and those of D. sampoi (B-form) (f-l. Ismail et al., 2009). Similarities suggest the two taxa may be synonymous.

Fadaei (2014) is uncertain, at least in terms of identity and very doubtful in terms of age.

Geographic Distribution: This species appears to be restricted to Egypt and the Arabian Plate (Eastern Neotethys). Although the type material was from Qatar, Henson (1948b) also reported the species from Jordan, the Levant region and Iran. In addition, Whittaker et al. (1998) reported it from Iraq, Kuwait and Yemen although it is possible that some of these records are referable to other Dicyclina species, especially D. schlumbergeri , as Whittaker et al. (1998) report an unexplained age-range for D. qatarensis as Turonian-Maastrichtian.