Dallina Temporal range:
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Dallina septigera, 23mm wide, recent | |
Scientific classification | |
Kingdom: | |
Phylum: | |
Class: | |
Order: | |
Suborder: | |
Superfamily: | Terebratelloidea
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Family: | |
Genus: | Dallina Beecher, 1893
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Species | |
See text |
Dallina is a genus of small to average size lampshells (maximum 35 millimetres or 1.4 inches long). [1] It is known since the Miocene.
Small to large, triangular to subquadrangular in outline; rectimarginate to paraplicate; beak erect, without beak ridges; foramen small to large, mesothyrid, attrite, symphytium concave. Hinge teeth small, weak; pedicle collar very short. Cardinalia lamellar with excavate inner and outer hinge plates separated by narrow crural bases; inner hinge plates converging on median septum to form V-shaped septalium; cardinal process not differentiated; median septum low anteriorly, extending beyond midvalve; adult loop teloform. [2]
Nine extant species are recognized (though one has recently been synonymized), [3] these are listed below:
Dallina Temporal range:
| |
---|---|
Dallina septigera, 23mm wide, recent | |
Scientific classification | |
Kingdom: | |
Phylum: | |
Class: | |
Order: | |
Suborder: | |
Superfamily: | Terebratelloidea
|
Family: | |
Genus: | Dallina Beecher, 1893
|
Species | |
See text |
Dallina is a genus of small to average size lampshells (maximum 35 millimetres or 1.4 inches long). [1] It is known since the Miocene.
Small to large, triangular to subquadrangular in outline; rectimarginate to paraplicate; beak erect, without beak ridges; foramen small to large, mesothyrid, attrite, symphytium concave. Hinge teeth small, weak; pedicle collar very short. Cardinalia lamellar with excavate inner and outer hinge plates separated by narrow crural bases; inner hinge plates converging on median septum to form V-shaped septalium; cardinal process not differentiated; median septum low anteriorly, extending beyond midvalve; adult loop teloform. [2]
Nine extant species are recognized (though one has recently been synonymized), [3] these are listed below: