Biplanata peneropliformis Hamaoui & Saint-Marc, 1970

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 : 62-64

Biplanata peneropliformis Hamaoui & Saint-Marc, 1970

Reference Illustration & Description Hamaoui & Saint-Marc (1970), Pls. 1-11, Fig. 1 , p. 262- 282.

The description and illustrations of the types in the original publication are excellent and comprehensive. See also Saint-Marc (1974a: plate 5) although some images are duplicated. See the Species Key Chart (Appendix) for diagnostic and other characteristics.

Biplanata possesses an internal plate centrally located within each chamber, which serves to distinguish from similar planispiral forms such as Daxia , Mayncina , Charentia , and Neodubrovnikella turonica . Superficially similar to Biconcava bentori , B. peneropliformis has a more flattened, disc-like test, has faster-growing chambers and lacks the V-shaped chamber cross section of the former. Externally it is a virtually complete homeomorph of Choffatella (see Fig 13a herein).

Whittaker et al. (1998), after re-examining Henson’s types of Mangashtia viennoti ( Henson, 1948) and comparing them with the description of B. peneropliformis by Hamaoui and Saint-Marc (1970), suggested that Henson’s specimens were similar and that Mangashtia viennoti Henson was therefore the senior synonym of B. peneropliformis . In our view (and that of Dr Felix Schlagintweit, pers. comm., 2023) Henson’s material conforms to the concept and (emended) definition of M. viennoti by Fourcade et al. (1997; see figs. 5-7) much closer than it does to B. peneropliformis . Mangashtia may include a small juvenile planispiral growth phase ( Henson, 1948, but not observed by Fourcade et al., 1997) but is primarily annular/cyclic in adult growth. The presence of structures in the centre parts of the chambers give the impression of a two-layered mode of growth which in axial and subaxial sections somewhat resembles the presence of the bisecting dental plate in Biplanata . Mangashtia however has many more annular chambers and Biplanata is entirely planispiral (and later uncoiled). The periphery of B. peneropliformis is also much more angular than that of M. viennoti . Fourcade et al. (1997) suggested a clear stratigraphic separation of the occurrence of B. peneropliformis (Cenomanian) and M. viennoti (Turonian) in their studied section in the Iranian Zagros. Nonetheless, it is possible that some records of M. viennoti in the literature may be misidentifications that are in fact B. peneropliformis (e.g., Omidvar et al., 2014a, b).

Biplanata differs from Demirina and Merlingina (all three genera are in the Nezzazatidae family) in being flatter throughout and having a fairly uniform axial chamber width throughout the height of the chamber compared with the distinctly wider parts in the middle and upper parts of the chamber height in Demirina and Merlingina respectively.

Stratigraphic Distribution

Uppermost early?/middle - late (but not latest?) Cenomanian.

The genus Biplanata (as nomen nudem – no type species) was first mentioned by Hamaoui (1965), based on material found in the Cenomanian Hazera Formation of Israel. Biplanata and B. peneropliformis were subsequently formally described from the Cenomanian (undifferentiated) of the Negev, Israel, and the late Cenomanian of Lebanon ( Hamaoui & Saint-Marc, 1970). It is worth noting that Arkin & Hamaoui (1967) regarded Biplanata as ranging throughout the Cenomanian of Israel, but this view was not held by Hamaoui (in Schroeder & Neumann, 1985) who described B. peneropliformis as having a range from the upper part of the early Cenomanian to the Cenomanian-Turonian boundary.

This species is commonly recorded in the literature, but most records are not substantiated by illustration. Similarly, few records are supported by independent age verification, which hinders assessment of stratigraphic range. Overall, records are almost entirely confined to the Cenomanian although skewed towards the middle – late Cenomanian.

Rare younger (e.g., Turonian) records (e.g., Philip et al., 1978; Arnaud et al., 1981) are not substantiated by plausible illustration. Fragmentary specimens from “Senonian” strata from southern Italy (Luperto- Sinni, 1976) described as B. peneropliformis , cannot be confirmed as these species, and can be discounted.

Extension of the range of B. peneropliformis into (basal) Turonian strata is based on information from Lebanon (e.g., Saint-Marc, 1974a, 1978, 1981), and as with a number of other taxa, this age assignment needs review. The species occurs in beds that from associated ammonite data appear to straddle the Cenomanian – Turonian boundary, but the precise stratigraphic position of B. peneropliformis occurrences relative to these ammonite occurrences is uncertain. Given this, and the lack of any other substantiated Turonian records, B. peneropliformis is excluded from the Turonian. This agrees with the (unillustrated) record of Parente et al. (2008) who use carbon isotope stratigraphy to suggest B. peneropliformis does not extend about the geslinianum ammonite zone. See also Schlagintweit & Yazdi-Moghadam (2022a) for discussion of Turonian records from Lebanon. A possible illustrated record from the alleged Santonian of the Zagros ( Kiarostami et al., 2019) must be a drafting error as the section contains Pseudolituonella reicheli Marie and Chrysalidina gradata d’Orbigny amongst other typically Cenomanian taxa.

The oldest records of B. peneropliformis are poorly constrained by independent age calibration, but the plausible illustrated records from Serbia ( Radoičić, 1974a); southern Turkey ( Tasli et al., 2006; Sari et al, 2009; Koç, 2017; Solak et al., 2020; Solak, 2021; and Simmons et al., 2020b), the Iranian Zagros ( Sampò, 1969 (as Nezzazata sp. ); Ezampanah et al., 2020; Mohajer et al., 2021a; Schlagintweit & Yazdi-Moghadam, 2022a; plus numerous unverified records (e.g., Afghah et al., 2014; Mehmandsoti, 2021); central Italy ( Chiocchini et al., 2012 – see also Foglia, 1992; Bravi et al., 2006; Borghi & Pignatti, 2006; Parente et al., 2007, 2008; Chiocchini, 2008a and Simone et al., 2012 for unillustrated records); and Albania-Kosovo ( Consorti & Schlagintweit, 2021a) are mostly middle – late Cenomanian based on associated microfauna, with only possible extension into the early Cenomanian (the upper part) for some. Other plausible records such as those from Greece ( Fleury, 1971), Croatia ( Velić & Vlahović, 1994), Syria ( Ghanem & Kuss, 2013 – but not figure 14/40 which might be more compatible with Merlingina cretacea ) and Egypt ( Shahin & Elbaz, 2013), are in keeping with this stratigraphic range assessment. Records that show B. peneropliformis ranging throughout the Cenomanian (e.g., Velić, 2007 for the Dinarides (see also Husinec et al., 2000, 2009)) are typically unsubstantiated by illustration.

Cenomanian Paleogeographic Distribution

Caribbean – Neotethys.

In addition to the records mentioned above, a key reference that extends the palaeogeographic range of this species is Bomou et al. (2019) who illustrate the species from the late Cenomanian of Mexico (see also no or uncertain illustration by Michaud et al., 1984; Hernández-Romano et al., 1997; Aguilera-Franco et al., 2001; Aguilera-Franco, 2003 and Aguilera-Franco & Allison, 2004).

There are numerous records with either no or questionable illustration that could, if proven by new data, further demonstrate the geographic distribution of this species and extend it much more widely. These records (west to east) include; Morocco ( Ettachfini, 2006; Piuz & Meister 2013), Iberia, including Spain and Portugal ( Berthou, 1984b; Calonge et al., 2003; Gräfe, 2005; Caus et al., 2009; Vicedo et al., 2011; Consorti et al., 2016b), southern France ( Deloffre & Hamaoui 1979); Kosovo ( Consorti & Schlagintweit, 2021b); Libya ( Dufaure et al., 1984); Slovenia ( Jež et al., 2011); Greece ( Decrouez 1976, 1978; Tsaila-Monopolis, 1977; Fleury, 1980; Pomoni-Papaaioannou & Zambetakis-Lekkas, 2009); Jordan ( Al-Rifaiy et al., 1994; Schulze, 2003 and Schulze et al., 2004), southern Iraq ( Bernaus & Masse 2007); and Oman ( Smith et al., 1990; Kennedy & Simmons, 1991; Piuz and Meister, 2013).

Figures

Fig. 1 Anonymised snapshot of a figure caption from a 2016 paper (by a major publisher) with four taxa spelled incorrectly.

Fig. 13 Representative illustrations of Biplanata peneropliformis: a External equatorial view, Hamaoui & Saint Marc (1970, pl. 5, fig. 3, Israel, holotype); b Oblique equatorial section, Saint Marc (1974, pl. V, fig. 1, Lebanon); c Axial section, Hamaoui & Saint Marc (1970, pl. 6, fig.2, Lebanon).