Dicyclina sampoi Cherchi & Schroeder, 1990b

Simmons, Michael, Bidgood, Michael, Consorti, Lorenzo & Schlagintweit, Felix, 2025, A Review Of The Identity And Biostratigraphy Of Cenomanian “ Larger ” Benthic Foraminifera: Part 2 - The Order Loftusiida (Excluding The Suborder Orbitolinina), Acta Palaeontologica Romaniae 21 (1), pp. 103-192 : 162-164

Dicyclina sampoi Cherchi & Schroeder, 1990b

Figure 26

? 1965 Dicyclina sp – Hamaoui, pl. 13, fig. 12; Cenomanian, Israel.

1969 Dicyclina sp. – Sampò, pl. 43, fig. 8 (non pl. 43, fig. 16;? pl. 43, figs. 7, 9, 14, 15); middle – late Cenomanian, Iranian Zagros.

1988 Dicyclina sp. – Sartorio & Venturini, p. 114 (upper fig.); Cenomanian, Iranian Zagros.

T 1990b Dicyclina sampoi n. sp. Cherchi & Schroeder, p. 204-210, figs. 10-23; middle-late Cenomanian, Iranian Zagros.

2009 Dicyclina sampoi – Ismail et al., p. 402, pl. 2, figs. 1-11 [not 3, 5, 9 =? D. qatarensis – see that species herein]; late Cenomanian, Egypt.

2012 Dicyclina schlumbergeri – Rahimpour-Bonab et al., fig. 8G; Cenomanian – Turonian, Iranian Zagros.

2013 Dicyclina schlumbergeri – Rahimpour-Bonab et al., fig. 8U; Turonian (?), Iranian Zagros.

Non 2013 Dicyclina sampoi – Ghanem & Kuss, fig. 13 (20-21); middle Cenomanian, Syria. [=? D. simplex ].

2014b Dicyclina schlumbergeri – Omidvar et al., fig. 3.10; Cenomanian, Iranian Zagros ( fide Schlagintweit & Rashidi, 2018 ).

2018 Dicyclina sampoi – Schlagintweit & Rashidi, fig. 6; Cenomanian, Iranian Zagros.

? 2018 Dicyclina sampoi – Omidi et al., pl. 2, fig. 11; Cenomanian, Iranian Zagros [= Dicyclina sp. ].

2019 Dicyclina schlumbergeri – Saedi Razavi et al., pl. 1, fig. 3; Cenomanian, Iranian Zagros.

2020 Dicyclina sampoi – Solak et al., fig. 10U; late Cenomanian, Western Taurides, Türkiye.

? 2021 Dicyclina sampoi – Gholamalian & Fanati Rashidi, pl. 3, figs 2-3; Cenomanian, Iranian Zagros [= Dicyclina sp. ].

? 2023 Dicyclina schlumbergeri – Al-Salihi & Ibrahim, pl. 1, fig. E; middle – late Cenomanian, southern Iraq.

Reference Images: Schlagintweit & Rashidi (2018) fig. 6; Solak et al. (2020); fig. 10U.

Taxonomy/Identity: First described from the middle-late Cenomanian of the Iranian Zagros by Cherchi & Schroeder (1990b), based in part upon an illustration of a Dicyclina sp. by Sartorio & Venturini (1988), D. sampoi differs from other Dicyclina species in the characteristically hook-shaped nature of its septa in transverse section (even “S”-shaped in some views, perhaps depending on section orientation) and with subepidermal partitions confined to attachment to the inside of the outer wall and not both the wall and septa like D. schlumbergeri (however, see below). It may be difficult to observe but the secondary chamberlets in the upper part of the supra-embryonic zone and the lower part of the sub-embryonic zone are also less well developed in D. schlumbergeri .

Cherchi & Schroeder (1990b) stated that “… D. sampoi cannot be integrated in the evolutionary lineage characterised by D. simplex and D. schlumbergeri …” (1990b, p. 210 as hypothesised by them in 1990a) and conclude that this demonstrates polyphyletic origins of Dicyclina species. They suggest a “European” origin for D. schlumbergeri and D. simplex and a Near and Middle East origin for D. sampoi .

Cherchi & Schroeder’s types (1990b) show transverse chamber partitions (“rafters”) confined to the inner side of the outer wall between the septa and they describe this feature as one of the ways of distinguishing D. sampoi from D. schlumbergeri (which has rafters on both surfaces). However, some illustrated occurrences of D. sampoi appear to also show rafters on the inner part of the septal wall as well as the chamber roof (e.g., see Rahimpour-Bonab et al., 2012, fig. 8G; Rahimpour-Bonab et al., 2013, fig. 8U; Omidvar et al., 2014b, fig. 3(10); Solak et al., 2020, fig. 10U). It is possible, therefore, that that these two species may only be distinguished by their respective supra- and subembryonic characteristics.

The specimen of D. sampoi illustrated by Ghanem & Kuss (2013) from Syria (especially fig. 13(20)) does not show the characteristic “hook- shaped” septa of D. sampoi in transverse view, whilst the embryonic apparatus (fig. 13(21)) seems to fit that of D. simplex .

Confident Stratigraphic Range: middle – late Cenomanian (common).

Uncertain Stratigraphic Range: Turonian.

The species was first described (as Dicyclina sp. ) from probable middle – late Cenomanian of the Iranian Zagros ( Sampò, 1969; Cherchi & Schroeder, 1990b). Since then, it has been recorded from the late Cenomanian of the Turkish Taurides ( Solak et al., 2020) and Egypt ( Ismail et al., 2009). Most records come from the undifferentiated Cenomanian of the Zagros (e.g. Schlagintweit & Rashidi, 2018), although Rahimpour-Bonab et al. (2013) present evidence that it can be found in the Turonian part of the Sarvak Formation in this region. However, the very same specimen illustrated is given an undifferentiated Cenomanian – Turonian age by Rahimpour-Bonab et al. (2012) and a Cenomanian age by Omidvar et al. (2014b).

Geographic Distribution: The vast majority of verified records of this species come from the Iranian Zagros with a single record from Egypt and a record from the Turkish Taurides.

Figures

Fig. 26. Representative illustrations of Dicyclina sampoi: a. Axial section (labelled as D. schlumbergeri by Omidvar et al., 2014b – reclassified as D. sampoi by Schlagintweit & Rashidi (2018, fig. 6a, Cenomanian, Iranian Zagros); b. Detail of a, Cherchi & Schroeder (1990b, fig. 13, Iran); c. Schematic detail of b, Cherchi & Schroeder (1990b, fig. 10a); d. Oblique transverse section (partial), Cherchi & Schroeder (1990b, fig. 17, Iran).