Hemicyclammina whitei ( Henson, 1948 )

SIMMONS, MICHAEL & BIDGOOD, MICHAEL, 2023, “ Larger ” Benthic Foraminifera Of The Cenomanian. A Review Of The Identity And The Stratigraphic And Palaeogeographic Distribution Of Non-Fusiform Planispiral (Or Near-Planispiral) Forms, Acta Palaeontologica Romaniae 19 (2), pp. 39-169 : 86-88

Hemicyclammina whitei ( Henson, 1948)

Reference Illustration & Description

Simmons & Bidgood (2022) p. 27-30, figs. 1-4.

The status of H. whitei with respect to its senior synonymy with H. sigali Maync and a number of other taxa have been discussed by Simmons & Bidgood (2022). They noted that when Maync (1953b) introduced the genus Hemicyclammina , he was seemingly unaware of the publication of Henson (1948) that introduced “ Cyclammina whitei ”. Examination of type and associated material indicates that this species is identical to H. sigali and thus should be regarded as the type species of the genus. See the Species Key Chart (Appendix) for diagnostic and other characteristics.

The alveolar nature of the wall but with solid, pointed septa which do not reach the previous whorl in equatorial section is characteristic. The solid (“semi-” or “hemi-”) septa serve to distinguish the genus from Buccicrenata with alveolar septa which are continuous outgrowths of the alveolar chamber wall. Pseudocyclammina is also similar but in addition to alveolar septa also has multiple apertures compared to the single slit of Hemicyclammina . Everticyclammina Redmond (Late Jurassic – Early Cretaceous) is very similar in almost every respect, but its aperture is areal rather than extending upwards from the base as in Hemicyclammina and which is also rather large, resulting in shorter septa. The poorly known genus Alveocyclammina Hillebrandt from the lower Albian of Peru ( Hillebrandt, 1971) is also similar possessing an alveolar wall, but its septa are also alveolar and appear to be very short.

The following poorly known taxa are considered by Simmons & Bidgood (2022) to be probable synonyms of H. whitei : Hemicyclammina evoluta Hamaoui , Ismailia neumannae El-Dakkak , and Sinainella aegyptiaca El-Dakkak. I. neumannae continues to be a name used in the Egyptian literature for specimens that might be H. whitei , although with external views that are not diagnostic (e.g., Shahin & El Baz, 2021). A specimen illustrated from the late Cenomanian of Egypt as Charentia cuvillieri Neumann by El-Sheikh and Hewaidy (1998) looks close to H. whitei .

Charentia hasaensis Basha , Charentia rummanensis Basha and Lituola hasaensis Basha are poorly known species introduced from material from the late Cenomanian of Jordan ( Basha, 1978). From the limited illustrations they may be partly synonymous with H. whitei . The type material needs to be re-examined. The same author reports but does not illustrate C. cuvillieri from the same rocks as his new species and he also reports the occurrence of H. sigali and H. whitei , but without illustration. Likewise, Charentia granulosa Kerdany & Eissa , described from the late Cenomanian of Egypt ( Kerdany et al., 1973), may include H. whitei amongst its types.

Dimitrova (1995) described “ Pseudonummoloculina sp. ” from the Cenomanian of Bulgaria and compared it to P. aurigerica . However, her illustration appears to have closer affinity to H. whitei .

Stratigraphic Distribution

Early Albian – intra-Late Cenomanian.

Simmons & Bidgood (2022) have reviewed the stratigraphic distribution of H. whitei and its common synonym H. sigali . H. whitei was first described ( Henson, 1948) from the Dukhan-3 well in Qatar at a depth of 3542-3543’. Although said to be “probably early Cenomanian”, this depth equates to the Mauddud/Nahr Umr Formation boundary and is of latest Albian age ( Bromhead et al., 2022). Henson (1948) also recorded the species from the Nahr Umr Formation at Rumaila- 1 in Iraq, suggestive of an Albian age ( Aqrawi et al., 2010). The type material of H. sigali is from the middle Cenomanian of Algeria ( Maync, 1953b).

Records commonly show a general composited Albian-Cenomanian age range. See, for example: Ansary et al. (1962); Wynd (1965); Sampò (1969); Kalantari (1992); Shirazi (2009); Shirazi et al. (2011); Omidvar et al. (2014a, b) from the Iranian Zagros; Saint-Marc (1970, 1974 a, 1981) from Lebanon; Simmons & Hart (1987), Forbes et al. (2010) from Oman; and general summaries by Saint-Marc (1977); Sartorio & Venturini (1988), and Schroeder et al. (2010). Statements that the species does not range above the Albian (e.g., Afghah & Dookh, 2014) should be discounted at both a local and inter-regional level.

Hart et al. (2005) recorded H. sigali (= H. whitei ) from strata in Portugal confidently assigned to the guerangeri and geslinianum ammonite zones of the late Cenomanian, following earlier records by Berthou (1973); Lauverjat (1976) and Crosaz-Galletti (1979). Saint-Marc (1981) reported the species from latest Cenomanian strata in Lebanon with the ammonites Eucalycoceras palaestinense (Blackenhorn) and Protacanthoceras angolaense (Spath) and planktonic foraminifera Helvetoglobotruncana praehelvetica (Trujillo) and Whiteinella spp. These records confer an upper range age limit of intra-late Cenomanian.

Pre-Albian records of the species are believed to be of a potentially ancestral form (“ Hemicyclammina ? sp.”) and include those of Hosseini et al. (2016) who illustrate material under the name H. sigali from the Barremian Gadvan Formation of the Iranian Zagros. However, the specimens are very small (0.2 – 0.3 mm in diameter), and the presence of an alveolar wall is not demonstrated.

A similar, slight larger (0.3 mm diameter) specimen has been illustrated by Özkan and Altiner (2019) from the early Aptian of south-east Turkey as “ Hemicyclammina ? sp.”.

Cenomanian Paleogeographic Distribution

Broadly across Neotethys, the Atlantic and the Caribbean. H. whitei has a broad palaeogeographic distribution across Neotethys and seemed to thrive in marly sediments deposited on middle – outer shelves. Confirmed records in addition to those previously mentioned above include from Brazil ( Berthou & Bengtson, 1988); Mexico ( Omaña et al., 2019); Morocco ( Andreu et al., 1996); Turkey ( Bignot & Poisson, 1974); Jordan ( Weidich & Al-Harithi, 1990); Saudi Arabia (Dr. Wyn Hughes, pers. comm., 2022); Abu Dhabi ( Banner, 1970), and Somalia ( Luger, 2018). Unillustrated records are known from numerous intermediate locations (Pyrenees – Peybernès, 1984; Tunisia – Robaszynski et al., 2010; Libya – Megerisi & Mamgain, 1980; Italy – Simone et al., 2012; Croatia – Husinec et al., 2000; Serbia – Radoičić and Schlagintweit, 2007; Kuwait – Youssef et al., 2019), and possibly Tibet ( BouDagher-Fadel et al., 2017).