Br@chNet
Aerothyris

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

 
 
 
 
 


Genus Aerothyris Allan, 1939
[Type species= Magellania macquariensis Thomson, 1918 (p. 30)]

Medium size, variably ovate, weakly to moderately unisulcate, smooth; beak suberect, attrite, foramen medium to large, mesothyrid, deltidial plates commonly disjunct, rarely conjunct in some adults. Cardinalia moderately thickened; outer hinge plates prominent and gently inclined; inner hinge plates more steeply inclined, uniting medianly to form septalium; cardinal process prominent, consisting of striated transverse myophore; crura with prominent crural processes; median septum bladelike; adult loop teloform.

Present

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

Extant Species of Aerothyris
  • A. macquariensis (Thomson, 1918)
  • A. kerguelensis (Davidson, 1878)
    		•  Diagnosis
    Diagnosis

    Aerothyris

    Aerothyris macquariensis  (Thomson, 1918)

    Type locality: "on beach above present high-water level, Wireless Cove, north-west end of Macquarie Island; over an extent of ¼ mile.”
    Depth range: 50 - 714 m

    Magellania macquariensis Thomson, 1918

    Diagnose in preparation -

     

    Should be added:
  • Muscle disposition: see Fig. in front - characteristic posterior notch between the two ventral adductor muscle scars.

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    ML

    Muscle attachment (modified, from Foster, 1974 - with absence of separate posterior accessory diductor muscles base, the pair of ventral adductor muscle bases in &a single unit)

     

    Aerothyris kerguelensis  (Davidson, 1878)

    Type locality: “dredged by the 'Challenger' Expedition off Marion Island, west of Kerguelen Isle, in a depth of 100 fathoms, and also in lat. 50°4'S., long. 71° 22' E., at a depth of 150 fathoms” (South Africa)
    Depth range: from some meters – more than 500 m

    Waldheimia kerguelensis Davidson, 1878
    Waldheimia dilata Lamarck: Smith (1879)
    Terebeatella dorsata Davidson, 1880
    Magellania kerguelensis: Eichler (1911) – See also Aneboconcha eichleri.
    Magellania kerguelenensis: Jackson (1918)
    Aerothyris eichleri Allan, 1939
    Magellania kerguelenensis: Foster (1974)
    Macandrevia kerguelensis: d’Hondt (1977)
    Magellania kerguelensis: Zezina (1980)
    Aerothyris kerguelenensis: Cooper (1981)

     

    Diagnose in preparation -

     

    Should be added:
  • Muscle disposition: see Fig. in front -
    		•  Nota:
    • The original species name by Davidson (1878, p. 431) is kerguelensis not kerguelenensis as written by several latter authors (see above); none of them got an explanation for this change of the original name. Hiller (1994, p. 72) used erroneously the name kerguelenensis for all synonyms. Consequently, the correct name remains kerguelensis according to article 32.1 of the International Code of Zoological Nomenclature (1999), which is applied herein.

    • The genus name, Magellania Bayle, 1880 or Aerothyris Allan, 1939, remains under debate for this species. Cooper (1981) pointed out that A. kerguelensis retains a smooth-shell into the adult stages, which is an important characteristic according to Allan (1939).  Hiller (1994) confirms this statement. Typical Magellania shows strong costae developed round the margins of mature shells. The use of such a taxonomical character to separate two genera remains questionable.

    ML

    Muscle attachment (modified, from Foster, 1974 - with absence of separate posterior accessory diductor muscles base, the pair of ventral adductor muscle bases in &a single unit)