Difference between revisions of "Glossary"
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* [[Alar prolongation]] - winglike extension of umbilico-lateral portions of involute chambers on lateral surfaces of previous whorls in lenticular tests. May be meandering. 182/1. 224/6. | * [[Alar prolongation]] - winglike extension of umbilico-lateral portions of involute chambers on lateral surfaces of previous whorls in lenticular tests. May be meandering. 182/1. 224/6. | ||
* [[Allopatric speciation]] - emergence of species by geographic isolation of populations for sufficient time to alter the genome of the populations involved to mutual reproductive incompatibility. | * [[Allopatric speciation]] - emergence of species by geographic isolation of populations for sufficient time to alter the genome of the populations involved to mutual reproductive incompatibility. | ||
| − | * [[Alternation of generations]] - see life cycle. | + | * [[Alternation of generations]] - see [[life cycle]]. |
* [[Alveolar layer]] - layer of alveoles in lateral chamber walls forming diagnostic exoskeletal structures lacking a differentiation of beams and rafters as well as polygonal subepidermal patterns, as in opposition to subepidermal, polygonal networks or keriothecal textures. | * [[Alveolar layer]] - layer of alveoles in lateral chamber walls forming diagnostic exoskeletal structures lacking a differentiation of beams and rafters as well as polygonal subepidermal patterns, as in opposition to subepidermal, polygonal networks or keriothecal textures. | ||
* [[Alveole (alveolus, pl. alveoli)]] - recess of varying depth coated by the organic lining in lateral chamber walls, blindly ending with a rounded contour below an epiderm or some equivalent outer layer of the wall and opening into the chamber lumen. May be branching towards the outer part of the wall, each generation of branches forming layers within the wall. | * [[Alveole (alveolus, pl. alveoli)]] - recess of varying depth coated by the organic lining in lateral chamber walls, blindly ending with a rounded contour below an epiderm or some equivalent outer layer of the wall and opening into the chamber lumen. May be branching towards the outer part of the wall, each generation of branches forming layers within the wall. | ||
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: Remarks: The term alveole is used here exclusively for exoskeletal structures, i.e. for subepidermal, tiny compartments of the chamber cavity coated by organic lining. Alveoles must be distinguished from paraporous or keriothecal cavities belonging to the wall texture. The latter are (by definititon) not filled with living chamber plasm nor coated by the organic lining. The simultaneous presence of both alveolar structures and keriothecal wall texture in the fusulinid Verbeekina and its relatives, the combination of an alveolar exoskeleton with a paraporous external wall in Dicyclina or with a bilamellar perforate wall in Fabiania supports a consequent restriction of the term's use to exoskeletal structures, never to textures. | : Remarks: The term alveole is used here exclusively for exoskeletal structures, i.e. for subepidermal, tiny compartments of the chamber cavity coated by organic lining. Alveoles must be distinguished from paraporous or keriothecal cavities belonging to the wall texture. The latter are (by definititon) not filled with living chamber plasm nor coated by the organic lining. The simultaneous presence of both alveolar structures and keriothecal wall texture in the fusulinid Verbeekina and its relatives, the combination of an alveolar exoskeleton with a paraporous external wall in Dicyclina or with a bilamellar perforate wall in Fabiania supports a consequent restriction of the term's use to exoskeletal structures, never to textures. | ||
| − | : Layers of alveoles coating the lateral chamber wall are present in various agglutinated groups of which Cyclammina is the most prominent while Everticyclammina is an early extinct representative of an exoskeletal layer of exclusively undivided, shallow alveoles. The Neogene group of Textulariella (GrÚnhagen and Luterbacher, 1966) has branching alveoles. Among the porcelaneous foraminifera, Austrotrillina may be an unique group. In this genus, species with deep and branching alveoles (A. howchini, Adams, 1968) are said to evolve from earlier forms with layers of shallow, undivided alveoles. | + | : Layers of alveoles coating the lateral chamber wall are present in various agglutinated groups of which ''Cyclammina'' is the most prominent while ''Everticyclammina'' is an early extinct representative of an exoskeletal layer of exclusively undivided, shallow alveoles. The Neogene group of Textulariella (GrÚnhagen and Luterbacher, 1966) has branching alveoles. Among the porcelaneous foraminifera, ''Austrotrillina'' may be an unique group. In this genus, species with deep and branching alveoles (''A. howchini'', Adams, 1968) are said to evolve from earlier forms with layers of shallow, undivided alveoles. |
| − | : The term alveole is also used for rows of blind recesses in postseptal position over supplementary apertures in the previous septal face as in Subalveolina or Bullalveolina. We do not yet know, how to interpret (in terms of exo- or endoskeletal elements) these alveoles nor what might be their biological meaning. | + | : The term alveole is also used for rows of blind recesses in postseptal position over supplementary apertures in the previous septal face as in ''Subalveolina'' or ''Bullalveolina''. We do not yet know, how to interpret (in terms of exo- or endoskeletal elements) these alveoles nor what might be their biological meaning. |
* [[Annular arrangement]] - arrangement of concentric annular chambers. 81/6. 226/3. | * [[Annular arrangement]] - arrangement of concentric annular chambers. 81/6. 226/3. | ||
