Pseudorhapydionina dubia ( De Castro, 1965 )

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 : 114-117

Pseudorhapydionina dubia ( De Castro, 1965)

Reference Illustration & Description

De Castro in Schroeder & Neumann (1985), pls. 40-42, p. 88-91.

The treatment of the genus and species by De Castro in Schroeder & Neumann (1985) is comprehensive and allows for confident identification. See also more comments on the genus under P. laurinensis , the type species. However, Cherchi & Schroeder (1986) regard some of De Castro’s 1985 illustrations of P. dubia (pl. 42, figs. 6 & 15) as P. anglonensis .

Consorti et al. (2016b) provide useful illustration of P. dubia from the late Cenomanian of Spain (see also Calonge-Garcia, 1996; p. 34, pl. 2, figs. 4-7) together with a succinct description: “ Porcelaneous shell with subglobular to cylindrical morphology. The chambers in the early stage of growth are arranged in one and a half to two whorls. The specimens of the Iberian Ranges show four chambers in the first whorl and six or seven in the second one. The uncoiled adult stage consists generally of five cylindrical chambers. The globular early stage reaches a maximum diameter of 0.35 mm with an average of 0.29 mm. The seriate adult stage has an average length of 0.6 mm, and the height of the chambers is approximately 0.06 mm. The scarce centred sections show a proloculus of about 40 μm in diameter. The apertural face is convex and the aperture cribrate. The intercameral foramina are regularly disposed, forming a circular pattern with three concentric stipple rings in the septa. The chamber lumen is partially divided by radial septula, which number approximately 5-6 per quadrant in the seriate adult stage of growth. Septula are short and their thickness is less than 10 μm.” See the Species Key Chart (Appendix) for diagnostic and other characteristics.

When visible, the very early coiling may be streptospiral which may place this species as a miliolid rather than a soritid (De Castro in Schroeder & Neumann 1985).

P. dubia is very similar to the Central America endemic homeomorph P. chiapanensis but has fewer total coiled chambers (7-11 cf. 12-13); slightly fewer chambers in the seriate stage (3-7 cf. 4-9); septula which are thin and short (cf. thick and medium length); and more septula per quadrant in the seriate stage (7-9 cf. 5). Nonetheless, P. dubia occurs in the middle – late Cenomanian of Mexico as confirmed by illustration ( Aguilera-Franco, 2000; Aguilera-Franco et al., 2001).

It differs from P. laurinensis in having generally parallel sides (= cylindrical) in the seriate stage rather than flaring and non-depressed sutures. The more extensive presence of long radial septula in P. laurinensis is a key difference. P. dubia differs from P. anglonensis in possessing an uncoiled (seriate) stage, but also a smaller coiled stage and less well-developed septula. The two taxa are very similar and can be confused when a seriate stage is absent. Illustrations of P. dubia from the late Cenomanian of the Pyrenees by Bilotte (1984) may be P. anglonensis .

Scandonea phoenissa Saint-Marc and Charentia cuvillieri Neumann are also similar to P. dubia in that they have a short uncoiled rectilinear portion, but which is noncylindrical, and with a somewhat more compressed or lenticular initial stage and no internal septula.

Some (pl. 8, figs. 15-18) but not all of the forms illustrated by Hamaoui (1961) as “ Taberina sp. (sp. nov?)” from the Cenomanian of Israel may be synonymous with P. dubia . However, more research is required.

Stratigraphic Distribution

(Early Cenomanian) middle – late Cenomanian.

Arnaud et al. (1981) and Schroder & Neumann (1985) summarise the range of P. dubia as having an inception within the early Cenomanian, then ranging through the middle and late Cenomanian, into the early Turonian. A review of all the many records of P. dubia to date suggests that most specimens confirmed by illustration occur within the middle to late Cenomanian (although local ranges may be shorter). Indeed, the species was introduced from sediments of this age from southern Italy ( De Castro, 1965) classically attributable to the middle and late Cenomanian (see also De Castro in Schroeder & Neumann, 1985; Chiocchini et al., 2012). None of those records where a Turonian extension is suggested is supported by plausible or definite identification ( Saint-Marc, 1974a, 1978, 1981), and/or where identification is better (e.g., Fleury, 1980), the Turonian age itself is questioned (De Castro in Schroeder & Neumann 1985). An illustrated “Senonian” record by Tsaila- Monopolis (1977) from Greece is poorly preserved and needs further research into its chronostratigraphic calibration.

Calonge-Garcia (1996) regards the species as ranging from the middle Cenomanian to the top of the Cenomanian based on material from Spain.

P. dubia has been plausibly illustrated from the latest Cenomanian of Morocco ( Charrière et al. 1998; Ettachfini, 2006) (see also Ettachfini et al., 2005 unillustrated). Parente et al. (2007, 2008) calibrated the LAD of P. dubia in Italy to within the N. juddi ammonite zone although the specimens were not illustrated. Using carbon isotope stratigraphy, Frijia et al. (2015) placed the extinction of P. dubia just below the Cenomanian/Turonian boundary in Italy.

Records of P. dubia in the early Cenomanian are generally rare (e.g., Decrouez, 1978; Berthou and Lauverjat, 1979; Michaud et al., 1984; Golubic et al., 2006; Ghanem et al., 2012). Berthou (1973) is a key reference, but only illustrates specimens from the middle and late Cenomanian in Portugal, although expands the range into the early Cenomanian. Ghanem & Kuss (2013) provide reasonable evidence that the species ranges throughout the Cenomanian in northwest Syria. Mohammed (2005), who illustrated P. dubia from southern Iraq, thought it might range throughout the Cenomanian there, but the age calibration evidence for that is less clear.

Simone et al. (2012) reported a single P. dubia specimen from supposed latest Albian strata in Italy (in addition to more common occurrences recorded from middle and late Cenomanian strata). They remark that this occurrence is atypical (see also Decrouez & Moullade, 1974) but the age is supposedly supported by orbitolinid faunas from a few metres above the sample (which include Neoiraqia insolita (Decrouez & Moullade) , Paracoskinolina tunesiana Peybernes (= Carseyella tunesiana ) and Valdanchella dercourti Decrouez & Moullade ). This assemblage is a confusing mix of mid-Cretaceous and Early Cretaceous taxa. Carseyella tunesiana (late Aptian – early Albian, Solak, 2021) is probably misidentified, and the other taxa could be as young as middle Cenomanian ( Schroeder & Neumann, 1985). Furthermore, the identification of this particular specimen of P. dubia by Simone et al. (2012) is not confirmed by illustration, thus extending the range of the species into the late Albian appears unjustified.

In Mexico, Aguilera-Franco (2000, 2003); Aguilera-Franco et al. (2001), Aguilera-Franco & Allison (2004) and Aguilera-Franco & Romano (2004) defined a Total Range Zone for this species that encompasses the upper middle and lower upper Cenomanian (see also Michaud et al., 1984; Hernández-Romano et al., 1997; Bomou et al., 2019 – in the last-named paper P. dubia is illustrated, but it may well be P. chiapanensis ). But somewhat confusingly, and without explanation, in some figures and text they extend the range of this zone into the early Cenomanian. An upper middle to lower Cenomanian Total Range Zone broadly corresponds to the similarly aged “ P. dubia and P. laurinensis zone” in central Italy ( Chiocchini et al., 1979, 2008, 2012). In Egypt a zone of this name is restricted to the intra-late Cenomanian ( Shahin & Elbaz, 2013, 2014), a clear case of facies control on ranges and hence calibration of the zonation. Tasli et al. (2006) defined a “ Pseudorhapydionina dubia and Biconcava bentori Cenozone ” encompassing the entire middle and late Cenomanian, equivalent to the “ Pseudolituonella reicheli - Pseudorhapydionina dubia Concurrent Range Zone ” of Sari et al. (2009) (see also Solak et al., 2020, who also reviews past interpretations of age range). Velić (2007) considered P. dubia to range from middle – late Cenomanian in the Dinarides.

Cenomanian Paleogeographic Distribution

Caribbean - Neotethys.

Widely reported, P. dubia is the most widespread species of the genus, although records are not always confirmed by illustration.

Confirmed illustrated records are from: Mexico ( Aguilera-Franco, 2000; Aguilera-Franco et al., 2001); Portugal ( Berthou, 1973; Michaud et al., 1984) (also no or uncertain illustration by Berthou & Lauverjat 1979; Berthou, 1984b; Andrade, 2018); Spain ( Calonge-Garcia, 1996; Consorti et al., 2016b); Morocco ( Charrière et al. 1998; Ettachfini, 2006) (also no or uncertain illustration by Ettachfini et al., 2005); Algeria ( Vila, 1974) (the illustrations by Salhi et al. (2020) are indeterminate, but clearly not this species); Egypt ( Shahin & Elbaz 2013, 2014); (the illustrations by Orabi (1992) from Sinai are indeterminate but clearly not this species); Albania ( Consorti & Schlagintweit 2021b) (also no or uncertain illustration by Heba, 2008); Italy ( De Castro, 1965; Chiocchini & Mancinelli, 1977; De Castro in Schroeder & Neumann 1985; Sartorio & Venturini, 1988; Spalluto & Caffau, 2010; Chiocchini et al., 2012; Simone et al., 2012) (also no or uncertain illustration by Foglia, 1992; Borghi & Pignatti, 2006; Randazzo et al. 2020); Sardinia ( Cherchi & Schroeder, 1976); Serbia ( Radoičić, 1972, 1974a, b) (also no or uncertain illustration by Golubic et al., 2006); Croatia ( Velić, 1973; Velić & Vlahović, 1994, Brčić et al., 2017, 2021) (also no or uncertain illustration by Veseli, 1994; Husinec et al., 2000, 2009; Korbar et al., 2001, 2012; Velić, 2007); Kosovo (Schlagintweit & Rigaud, 2015); Greece ( Fleury, 1980) (also no or uncertain illustration by Fleury 1971; Decrouez & Moullade, 1974; Charvet et al., 1976; Decrouez, 1978; Zambetakis-Lekkas, 2006; Pomoni-Papaioannou & Zambetakis-Lekkas, 2009); Turkish Taurides ( Tasli et al., 2006; Sari et al., 2009; Koç, 2017; Robertson et al., 2020; Solak, 2021; Solak et al., 2017, 2019, 2020) (also no or uncertain illustration by Bignot & Poisson, 1974; Sağaltici & Koç, 2021); Jordan (Schulze et al., 2005) (also no or uncertain illustration by Kuss, 1994); Syria ( Ghanem and Kuss, 2013) (also no or uncertain illustration by Saint-Marc, 1977; Ghanem et al., 2012); Southern Iraq ( Mohammed, 2005) (also no and uncertain illustration by Hamaoui & Brun, 1974; Mohammed, 2007, Al-Salihi & Ibrahim, 2023).

Location records with no or questionable illustrations include: Mexico ( Hernández-Romano et al., 1997; Aguilera-Franco, 2003; Aguilera-Franco & Allison, 2004; Aguilera-Franco & Romano, 2004; Bomou et al., 2019); SE France ( Rineau et al., 2021); Tunisia ( Bismuth et al., 1967; Saïdi et al., 1995; Touir et al. 2017); Slovenia ( Šribar & Pleničar, 1990); Montenegro ( Božović, 2016); Israel ( Hamaoui, 1961); Lebanon ( Saint-Marc, 1970, 1974a, 1978, 1981); Iranian Zagros ( Mohajer et al., 2021a; Rahimpour-Bonab et al., 2013; Omidvar et al., 2014a, b; Consorti et al., 2015; Rikhtegarzadeh et al., 2016, 2017; Saeedi Razavi et al., 2019, 2021; Dehghanian & Afghah, 2021; Asghari et al., 2022). The illustration by Schlagintweit & Yazdi-Moghadam (2022a) is possible, but it also might be P. anglonensis (illustrating the difficulty of separating these taxa), or indeed something else. The illustrations from the Iranian Zagros by Kiarostami et al. (2012) Esfandyari et al. (2023), and Mohajer et al. (2022a) are all indeterminate but cannot be reconciled with this species.