Fig. 3 in Dictyoconella Henson, 1948, Upper Cretaceous Larger Benthic Foraminifera: A Taxonomic Revision With The Establishment Of Gusicella Gen. Nov. (Type-Species Dictyoconella Minima Henson)

Fig. 3 Dictyoconella complanata Henson from the Maastrichtian of Qatar (a-b) and Iran (c-e). a, isolated specimen, holotype (from Henson, 1948, pl. 6, fig. 2). Section planes 1-----1' and 2-----2' refer to b and d respectively. b, transverse section parallel to the median plane (from Henson, 1948, pl. 6, fig. 3, parataype). c, slightly oblique median section. Note the inclination of the chambers towards the apex. Thin section 2Ng 83. d-e, slightly oblique subaxial sections, perpendicular to the median plane (s = septum, f = foramen). Thin sections 2Ng 81, 2Ng 80-5. deuteroconch, eccentric position with twisted apex. Mi- Larger Benthic Foraminifera associated with dasycladale- crospheric embryo not discernible within a close-coiled an algae (Fig. 2). Gusicella minima occurs more common whorl. Adult chambers arched and rectilinear. Exoskelein the lower part of the Tarbur Fm. associated with Om- ton with several orders of horizontal and vertical partiphalocyclus and Loftusia (Wynd, 1965: Omphalocyclu- tions forming a delicate subepidermal network. The marclus-Loftusia assemblage zone), and other taxa such as ginal zone is separated from the central zone by a mar- Gyroconulina columelliforma Schroeder & Darmoian ginal trough. Central zone with pillars alternating be- (Fig. 2c-d). D. complanata is restricted to the upper part tween subsequent chambers. Foramina multiple in the of the Tarbur Formation in a more inner platform setting central zone and with straight arrangement between (compared to the occurrence of G. minima). Here it is chambers; marginal foramina are present. Wall finely associated with taxa such as Loftusia div. sp., Dicyclina agglutinated, thin, consisting of an epiderm and a delicate schlumbergeri Munier-Chalmas, Tarburina zagrosiana sub-epidermal cellular layer. Schlagintweit & Rashidi and Pseudonummoloculina Comparisons: Morphologically, Dictyoconella is unique kalantarii Schlagintweit & Rashidi (Fig. 2a-b). among all other Orbitolinidae due to its strongly compressed (flattened) test. This makes a detailed comparison SYSTEMATICS to the other Upper Cretaceous genera of the Orbitolinidae superfluous. Douglass (1960, p. 256) stated that "it is Phylum Foraminifera d'Orbigny, 1826 likely" that Dictyoconella "is merely a variant of the ge- Class Globothalamea Pawlowski et al., 2013 nus Iraqia". This assumption must be rejected because of Order Loftusiida Kaminski and Mikhalevich in Kamin- the difference in the central zone: reticulate in Iraqia (e.g. ski, 2004 Moullade, 1965) and pillaroid in Dictyoconella. It is Suborder Loftusiina Kaminski and Mikhalevich in Ka- worth noting at this point that the incorrect view of minski, 2004 Douglass was also approved by BouDagher-Fadel and Superfamily Orbitolinoidea Martin, 1890 Price (2009, p. 7) who included Dictyoconella in a group Family Orbitolinidae Martin, 1890 of "Orbitolinids with radial partitions that became zig- Subfamily Dictyoconinae Moullade, 1965 zagged, thickening and fusing centrally. Last but not Genus Dictyoconella Henson, 1948 emended herein least, neither Dictyononella complanata nor "D." minima Type-species: Dictyoconella complanata Henson, 1948. were treated in the revision of the Orbitolinidae by Cruz- Holotype P.35832 in Henson (1948), in repository at the Abad (2018) although the genus was considered valid by Natural History Museum London. Loeblich and Tappan (1987). Accessible from the origi- Diagnosis: Large-sized, laterally compressed test, flabel- nal samples of Qatar deposited at the Natural History liform. The test displays a distinct asymmetry, with one Museum in London (see pictures at nhm.ac.uk), the specside (with the eccentric embryo) that is wider (with re- imens were labeled Dictyoconella (Dictyoconus) comspect to the central axis) and presents a concave outer planata by Henson. In fact, Dictyconella is best described periphery in equatorial section. Test base distinctly con- as a distinctly compressed (flattened) Dictyoconus vex. Megalospheric embryo simple, biloculine with ellip- Blanckenhorn. Two specimens of Dictyoconella comsoidal protoconch and hemispherical to sickle-shaped planata were interpreted as microspheric specimens of