Scandonea? phoenissa Saint-Marc, 1974

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 : 133

Scandonea? phoenissa Saint-Marc, 1974

Reference Illustration & Description

Saint-Marc (1974b), Pl. 1 & 2 (not 16-18), p. 68-70.

The type description of the species by Saint-Marc (1974b, from the middle Cenomanian of Lebanon) is comprehensive and allows for confident identification .

De Castro (1971) introduced the genus Scandonea , with the type species as the Late Cretaceous (Turonian and younger) species S. samnitica . Based on the type species, Scandonea is a distinctive porcellaneous walled form, with initial coiling being milioliform/streptospiral, then planispiral involute. The type species has basal thickening to each chamber wall (for a recent review see Arriaga et al., 2016).

Saint-Marc (1974b) erected S.? phoenissa on the basis of differences from S. samnitica : smaller dimensions; a reduced number of whorls in the coiled planispiral stage; the lack of basal thickening inside the chambers, and the lack of a tooth in the aperture. These differences are sufficient to make the assignment to the genus questionable, and this rarely described species requires a full taxonomic review that is outside the scope of this primarily biostratigraphic study. See the Species Key Chart (Appendix) for diagnostic and other characteristics.

S? phoenissa is a poorly known species and the possibility exists that the type material is synonymous with species of Pseudorhapydionina (as partial, incomplete specimens) – compare, for example, with the illustrations of P. dubia herein. More work is required to confirm this suspicion (Dr. Lorenzo Consorti, pers. comm., 2023), so, for the moment, S? phoenissa is retained as a separate species.

S.? phoenissa is similar to S.? pumila Saint-Marc (see remarks under that species for distinguishing features).

Similar taxa include Moncharmontia apenninica and Charentia cuvillieri , but which are both planispiral throughout and agglutinated. The latter also tends to uncoil like some specimens of S.? phoenissa . In addition to the above differences, Moncharmontia compressa has a subangular periphery not observed in S.? phoenissa (or S.? pumila – see below).

Stratigraphic Distribution

(Latest Albian?) early - middle Cenomanian (earliest late Cenomanian?).

Not a widely recorded species, Saint-Marc (1974b) originally described this species from Lebanon from sediments containing Sellialveolina viallii (Colalongo) and Ovalveolina maccagnoae De Castro which were assigned a middle Cenomanian age. However, the associated taxa mentioned occur in early Cenomanian sediments, and possibly latest Albian ( Schroeder & Neumann, 1985). However, its occurrence is at the top of Saint-Marc’s P. viallii biozone, suggesting mostly likely a middle Cenomanian age. Subsequent plausible records are few. Solak et al. (2020) recorded and illustrated this species from the early – middle Cenomanian Sellialveolina gr. viallii zone in the western Taurides of Turkey, with a reported occurrence in the basal part of the late Cenomanian Pseudorhipidionina casertana zone.

Velić & Sokač (1979) illustrated plausible specimens from the supposed latest Albian of Croatia in association with a number of species of orbitolinids (e.g., “ Valdanchella ” dercourti ). These orbitolinids are not well illustrated and in any case might well be Cenomanian (see synonymy lists and range charts in Schroeder & Neumann, 1985). Subsequently, Husinec et al. (2000) recorded this species (unillustrated) from the lowest part of the Orbitolina (Conicorbitolina) conica abundance zone of Croatia, attributing this zone to the early – middle Cenomanian. However, Husinec et al. (2009) later indicated the range of this species in Croatia as latest Albian only. Meanwhile, Velić (2007) recorded this species (unillustrated) from the late Albian of Croatia, noting in the text (not the range chart), that the species range extends into the Late Cretaceous (i.e., Cenomanian). In summary, there are question marks regarding the late Albian age attribution of records in Croatia, stemming from uncertainty in the associated orbitolinid identifications and their perceived biostratigraphic calibration. The late Albian records could well be proved to be early Cenomanian, pending further research.

Forms recorded and illustrated as Scandonea aff. phoenissa by Tešović et al. (2011) and, separately, by Ritossa (2018) also from Croatia are from strata dated variously between the Albian and Aptian. The illustrations in both sources are insufficient to assign a definite species (or genus) to the specimens and do not therefore affect the range attributed herein.

Cenomanian Paleogeographic Distribution

Central Neotethys.

Not widely recorded except from those references mentioned above (i.e., confirmed by illustration in Lebanon, Turkey, and Croatia). Records from Croatia appear to be common.