Pseudorhapydionina anglonensis Cherchi & Schroeder, 1986

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 : 112-114

Pseudorhapydionina anglonensis Cherchi & Schroeder, 1986

Reference Illustration & Description

Cherchi & Schroeder (1986), Pl. 1 (figs. 4, 6, 8-11), p. 188. First proposed in a 1985 field guide and declared nomen nudum by the authors in their 1986 publication.

P. anglonensis is atypical for the genus and may not even be correctly assigned to it (as indicated by Cherchi and Schroeder by a “?” in their original description) in that there is no uncoiled portion. Cherchi & Schroeder (1986) were unable to confirm the presence of a cribrate aperture except in the last few chambers and therefore questioned the generic assignment, but Consorti et al. (2016b) using material from Spain confirmed it from early chambers and thus the generic assignment. However, the total observed material is relatively limited in scope and abundance and uncoiled examples may be recorded in the future. Typical characteristics of the genus are discussed under P. laurinensis (De Castro) herein.

Solak et al. (2017) illustrated P. anglonensis from southern Turkey together with P. dubia . Their illustration of P. anglonensis (see Solak et al., 2017: fig. 8V) is very similar to the coiled stage of one of their P. dubia specimens (see Solak et al., 2017: fig. 8R). This leads to the suspicion that the former species is simply a juvenile (uncoiled) form of the latter (see also comparative illustrations herein) with which it often co-occurs, and this name should appear in synonymy with P. dubia . Further studies are needed to test this view.

P. anglonensis (as currently defined) differs from all other Pseudorhapydionina species in apparently lacking an uncoiled, seriate stage. It has 10-12 total coiled chambers and septula which are thin and medium, thickened peripherally. See the Species Key Chart (Appendix) for diagnostic and other characteristics.

It is broadly similar to Scandonea spp. and Moncharmontia spp. , but these do not have internal septula and, in the case of the latter, has more chambers. Note that some specimens described as P. dubia by De Castro in Schroeder & Neumann (1985) are considered as P. anglonensis by Cherchi & Schroeder (1986) and Mancinelli & Chiocchini (2006).

Fissumella motolae Cruz-Abad et al. , a genus and species introduced from the early Albian of Italy ( Cruz-Abad et al., 2017), resembles P. anglonensis with the presence of a few incomplete radial septula. However, these two genera differ in the nature of the aperture, which is cribrate in Pseudorhapydionina , but single and fissure-shaped in Fissumella .

Stratigraphic Distribution

Middle? – Intra-late Cenomanian.

Rarely recorded in the literature. Cherchi & Schroeder (1986) in their original description from Sardinia described the occurrence of P. anglonensis as late Cenomanian, a view upheld by Consorti et al. (2016b). Illustrations of P. dubia from the late Cenomanian of the Pyrenees by Bilotte (1984) may be P. anglonensis . However, in the Italian literature, where the species is often well illustrated (e.g., Mancinelli & Chiocchini, 2006; Chiocchini, 2008a, 2008b; Chiocchini et al., 2008, 2012), its occurrence is the lower part of the upper Cenomanian, where only a bipartite subdivision of the Cenomanian is used. This might equate to the middle Cenomanian or very low in the late Cenomanian of other authors.

Cenomanian Paleogeographic Distribution

Central Neotethys.

Recorded and plausibly illustrated only from Spain, Sardinia, Italy and the Turkish Taurides (see references mentioned above).