Br@chNet
Dallina

Sous-embranchement (subphylum) des Rhynchonelliformea
Classe des Rhynchonellata
Ordre des Terebratulida
Sous-Ordre des Terebratellidina
Super-famille des Terebratelloidea

 
 
 
 
 


Genus Dallina Beecher, 1895
[Type species= Terebratula septigera Lovén, 1846 (p. 29)]

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.

Miocene - Present

Diagnosis from volume 5 of the
Treatise on Invertebrate Paleontology (2006)

Extant Species of Dallina
  • D. septigera (Lovén, 1846)
  • D. floridana (Pourtalès, 1867)
  • D. raphaelis (Dall, 1870)
  • D. triangularis Yabe & Hatai, 1934
  • D. obessa Yabe & Hatai, 1934
  • D. elongata Hatai, 1940
  • D. profundis Konjukova, 1957
  • D. eltanini Foster, 1974
  • D. parva Cooper, 1981
  • D. tasmaniaensis Verhoeff, 2023
  • D. lusitanica Hansen, 2024
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    Diagnosis

    Diagnosis

    Diagnosis

    Diagnosis
    Diagnosis


    Dallina triangularis   Yabe & Hatai, 1934

    Type locality: "Sôyô-maru station 419, 32°12'10"N., 129°49'45"E., 402 m, bottom temp. 9.6°C."
    Depth range: 356 - 402 m.

    Diagnosis (Yabe & Hatai, 1934, p. 662, fig. 31-35)

    Shell resembling D. raphaelis (Dall), but differing in possessing a strongly triangular shell, being broadest anteriorly, more stronglycurved lateral commissure, small shell and different coloration. Length ca. 23.5, width 21, depth 16 mm.

     

        Facsimile of the text-fig of Yabe & Hatai (1934) - disposition modified >>

    Dallina lusitanica   Hansen, 2024

    Type locality: South Celtic Sea, off France, 47°11'-47°14'N, 6°11'-6°13'W, 1143 m depth.
    Depth range: 460 - 3000 m.

    Terebratula septata; Jeffreys (1878) [partim].
    Magellania septigera: Fischer & Œhlert (1891) [partim]; Joubin (1907).
    Dallina septigera: Atkins (1960a) [partim]; Brunton & Curry (1979) [partim]; Cooper (1981a); Anadón (1994); Logan (1998); Gaspard (2003); Anadón et al. (2022).

    Diagnosis (Hansen, 2024, p. 54, fig. 52-53)

    Moderately large Dallina species. Mature specimens characterised by their typically strongly subtriangular outline with greatest width close to anterolateral corners. Lateral commissure distinctly curved and anterior commissure gently to moderately parasulcate. Dorsal septum extended to approximately 80-90% of valve length.

        Facsimile of the text-fig of Hansen (2024) - disposition modified

    Dallina eltanini   Foster, 1974

    Type locality: “Stations USC 1345 (54°50'S, 129°48'W): 915-1153 m.”
    Depth range: 339 - 1208 m

    Diagnosis in preparation -


    Dallina tasmaniaensis   Verhoeff, 2023

    Type locality: seamounts south of Tasmania, 44.2394°S, 147.2929°E; 1354-1414 m depth, IN2018_V06 Stn 169, 14.12.2018, TMAG E58673.
    Depth range: 1157 - 1712 m.

    Diagnosis (Verhoeff, 2023, p. 12, fig. 5)

    Moderately large, thin shelled, and subtriangular Dallina, with relatively long beak, intraplicate anterior commissure (moderate folding), relatively broad symphytium, rectangular plate-like cardinal process, large crural processes supported by a straight-edged crura–descending branch junction, and relatively thick descending branches.

    From the Fig. 5 of Verhoeff (2023)