Difference between revisions of "Alcove"
(Created page with "thumb|<font size="2"> '''Fig. 1.''' The structure of ''Orbitopsella'': a simple [[exoskeleton and a pillared endoskeleton in a discoidal shell: ''Orbit...") |
|||
| Line 1: | Line 1: | ||
[[File:Fig 72.jpg|thumb|<font size="2"> '''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. | [[File:Fig 72.jpg|thumb|<font size="2"> '''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 [http://paleopolis.rediris.es/cg/CG2006_M02/index.html] '''CC'''/BY-NC-SA)]] | + | '''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 [http://paleopolis.rediris.es/cg/CG2006_M02/index.html] '''CC'''/BY-NC-SA)]] |
__FORCETOC__ | __FORCETOC__ | ||
==Definition== | ==Definition== | ||
