Fleuryana gediki Solak et al., 2020

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 : 73-75

Fleuryana gediki Solak et al., 2020

Reference Illustration & Description

Solak et al. (2020), p. 19, Figs. 14 (A-E) & 15.

This Turonian species (so far only known from its type locality in Turkey – Solak et al., 2020) is included herein because of its close similarity to Moncharmontia apenninica (De Castro) which can occur in the Cenomanian (see entry for that species). F. gediki is similar to M. apenninica in overall shape and structure but differs in having a single, arched slit basal aperture (see Solak et al., 2020, fig. 15G for an axial view), a thinner test wall (8 μm vs 17 μm) and fewer chambers (8, rarely 9 vs 9-10.5). It is also smaller (<0.40mm) in equatorial diameter than M. apenninica (> 0.40mm). In equatorial view its chambers are longer than high compared with M. apenninica’s which are shorter than high. Moncharmontia compressa (De Castro) is somewhat more compressed and lacks the well-rounded periphery. See the Species Key Chart (Appendix) for diagnostic and other characteristics.

F. gediki differs from the type species of Fleuryana , F. adriatica De Castro, Drobne & Gušić (described originally from the latest Maastrichtian of Croatia), in having a well-rounded, hemiglobular shell (cf. lenticular), fewer chambers and having the aperture in a basal position rather than central as in F. adriatica . The chambers in F. gediki are also distinctly rectangular in equatorial section. Biometric differences between F. gediki and M. apenninica & F. adriatica are tabulated by Solak et al. (2020; table 2).

The “canaliculate” wall (=pseudokeriothecal) described by Solak et al. (2020) is only highlighted on 3 out of 25 illustrations in their paper and is evidently not easy to determine in the relatively thin walls of F. gediki therefore its presence remains equivocal. The definitive presence of such a feature could also call for taxonomic separation of F. gediki from the genus Fleuryana (see discussion in Schlagintweit & Septfontaine (2023) for the species Siphopfenderina geyikensis (Solak)) . However, until better material becomes available this taxon can be retained in Fleuryana .

Stratigraphic Distribution

Turonian –?Coniacian.

Reported from “ levels following the extinction of Cenomanian benthic foraminifera… in the Bornova Flysch Zone and Bey Daglari [of SW Turkey]” (Solak et al., 2020). The type locality is from Turonian strata ( Pseudocyclammina sphaeroidea Zone sensu Solak et al., 2020 ) but it is also known from undifferentiated Turonian – Coniacian strata in the region close to the type locality.

Cenomanian Paleogeographic Distribution

Central Neotethys.

So far only recorded from the Taurides of SW Turkey (Solak et al., 2020).

Figures

Fig.14 Cenomanian paleogeographic distribution of Biplanata peneropliformis.