Fig. 1. The structure of Orbitopsella: a simple exoskeleton and a pillared endoskeleton in a discoidal shell: Orbitopsella dubari Hottinger, Bou Dahar, Eastern Morocco, Middle Lias. Transmitted light micrographs.A: oblique section of complete microspheric specimen; B: oblique section of microspheric specimen. The septa of the thickened margin are cut tangentially and reveal the alternating pattern in the disposition of foramina on the septal face. C: oblique tangential section of a microspheric specimen at a low angle to the equatorial plane showing a part of the disc with its exoskeleton (restricted to beams). Note the large open spaces, the lateral annular passages (arrows), that separate exoskeleton and endoskeleton. D: Oblique centered section of megalospheric specimen. Note the structured wall of the embryo, that shows it to be a sphaeroconch. E: Transverse section (parallel to the axis of coiling) of a megalospheric specimen. The septum in this tangential section reveals the alternating pattern of the apertures. F: schematic model of structure after Hottinger, 1967; not to scale; green: exoskeleton; brown: endoskeleton; a: aperture; ap: annular passage; b: beam; f: foramen; p: pillar; pr: sphaeroconch; s: septum; (Hottinger, 2006; fig. 72  CC/BY-NC-SA)
Fig. 2. Preseptal (prp) and postseptal (pop) passages. A: Alveolina munieri Hottinger (equatorial section of microspheric specimen, Middle Lutetian, S. Giovanni Ilarione, Northern Italy). B-E: unpublished plasticine models of the shell by M. Reichel. B-C: oblique views showing chamberlets. In C the chamber roof (spirotheca) is partly removed. D: side view of chamber showing septum and passages behind and in front of it. E: oblique view complementary to B showing main and intercalary apertures. the septal realm between two adjacent chambers. F-H: unpublished models of sarcode (=shell cavities) by M. Reichel seen from above (F), obliquely from the side (G) and from below (H); Arrows: direction of growth; bl: basal layer; chl: chamberlet; chlsut: chamberlet suture; chsut: chamber suture; f: foramen; icf: intercalary foramen; pop: postseptal passage; prp: preseptal passage; prwsurf: chamber roof surface of previous whorl; s: septum; sl: septulum; sup: supplementary passages in basal layer; sut: suture (of chambers); te: chamber roof (tectum); (Hottinger, 2006; fig. 79  CC/BY-NC-SA)
- according to Hottinger (2006):
PASSAGE – the means of communication between adjacent compartments of the same chamber; it is an opening that may be sited below the frontal chamber wall (preseptal), after the septal wall (postseptal) as in alveolinids, or at the fusion between exoskeleton and endoskeleton, as in verbeekinids. In peneropliform to concentric architectures, the passages may be semiannular-annular, in a preseptal position, as in Sorites, or paired in lateral positions, separating exoskeleton from endoskeleton, as in Anchispirocyclina or Orbitopsella.
Hottinger (1967), Foraminifères imperforés du Mésozoïque marocain, Notes et Mémoires du Service géologique, Rabat, N° 209, p. 5-168
Hottinger (2006), Illustrated glossary of terms used in foraminiferal research. Carnets de Géologie, Memoir 2, ISSN 1634-0744.
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