Deuterospira pseudodaxia Hamaoui, 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 : 58-60

Deuterospira pseudodaxia Hamaoui, 1965 emended Hamaoui, 1979

Reference Illustration & Description

Hamaoui (1979), Fig. 2 , p. 342.

Only two illustrations of this genus and species are thought to be published (in Hamaoui, 1966, 1979 and in Loeblich & Tappan, 1988).

Reported as a new genus and species by Hamaoui (1965) in a Geological Survey of Israel report, it was neither described nor illustrated. It was illustrated by Hamaoui (1966) in another GSI report but not otherwise described. This was corrected in both respects by Hamaoui (1979). Overall, Deuterospira is broadly similar to Daxia cenomana and Biconcava bentori , although it is believed to have only two full coils (from which the name is derived). Daxia and Biconcava on the other hand, can have up to 4-5 coils. The chamber divisions can apparently only be seen in the second coil, the first coil (in the holotype) is believed to be filled with agglutinated material which obscures any view of chamber partitions such as septa or inward projections into the chamber lumen as in Demirina (see below) which could suggest possibly synonymy with D. meridionalis (see also Loeblich & Tappan, 1988). The foramina are distinctly basal/interiomarginal in equatorial views (in the second coil at least) but are suggested to become more areal in later chambers ( Daxia ’s are areal throughout) although illustrated evidence is lacking. See the Species Key Chart (Appendix) for diagnostic and other characteristics.

Mayncina is also similar, but that genus is broadly biconvex compared with Biconcava , Daxia and Deuterospira and Mayncina also has multiple areal apertures.

D. pseudodaxia is also characterised by the sharpest periphery of the genera and species mentioned. Nonetheless, this genus and species remains very poorly known and more research on topotypic material is required to improve our understanding of its identity.

Stratigraphic Distribution

(Late?) Cenomanian.

Deuterospira pseudodaxia is rarely reported in the literature. Hamaoui (1965, 1966) described it from the Zafit - Avonon Members of the Hazera Formation of Israel, attributing a Cenomanian age (“probably upper part”) to the interval.

Hamaoui & Brun (1974) reported it (unillustrated) from the Mishrif Formation of Iraq, also attributing a Cenomanian (lower – upper) age (see also Hamaoui, 1979). Note that according to modern literature (e.g., Bromhead et al., 2022), the Mishrif Formation of southern Iraq is typically late Cenomanian – early Turonian, although usage varies.

Cenomanian Paleogeographic Distribution

Eastern Neotethys.

Limited distribution (see references mentioned above).

Figures

Fig. 2 Some morphological descriptions and visualisations of wall and/or chamber components of planispiral or part-planispiral LBF taxa. (a after Hamaoui & Saint-Marc, 1970; b-f after Hottinger, 2006; G: after Vicedo et al., 2013; h after Consorti et al., 2015; j after Consorti et al., 2018). Other abbreviations shown in image j are bl=basal layer; cs=conical spaces; if=intercameral foramina and sc=socculi crest.