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


Genus Neothyris Douvillé, 1879
[Type species= Terebratula lenticularis Deshayes, 1839 (p. 274)]

Large, smooth, weakly unisulcate, beak erect to incurved, foramen small, mesothyrid, attrite; deltidial plates conjunct. Strong posterior shell thickening in adults. Cardinalia thickened, crural bases fused with socket ridges; median septum short, high, bifurcating posteriorly to form wide hinge trough, almost filled by large, swollen boss of cardinal process; crura rather short, crural processes prominent; adult loop teloform.
Lophophore plectolophous.

Miocene - Present

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

Extant Species of Neothyris
  • N. lenticularis (Deshayes, 1839)
  • N. ovalis (Hutton, 1886)
  • N. westpacifica Zezina, 2001
  • Diagnosis

    Neothyris lenticularis   (Deshayes, 1839)

    Type locality: Foveaux Strait (Southern New Zealand)
    Depth range: 0 - 1210 m

    Terebratula gaudichaudii Gray, 1833 (not Blainville, 1828)
    Terebratula lenticularis Deshayes 1839 (p. 359)
    Waldheimia lenticularis Gray, 1853
    Neothyris lenticularis Douvillé, 1879
    Magellania lenticularis Suter, 1911
    Magellania (Neothyris) lenticularis Dall, 1921
    Neothyris obtusa Thomson, 1920
    Neothyris lenticularis compressa Naell, 1972
    Neothyris dawsoni Neall, 1972
    Neothyris parva Cooper, 1982
    ? Neothyris compressa Foster, 1989

    Diagnose in preparation -


    Fac-simile of the original description by Deshayes (1839).

    Should be added:
  • Muscle disposition: see Fig. in front - close proximity between the main and the accessory adductor muscles bases on the ventral side
  • Pedicle

    Disposition of the pedicle and pedicles muscles - sagittal section
    (from Richardson, 1979)


    Muscle attachment (modified, from Richardson, 1979; and
    from Foster, 1974 - with absence of separate posterior accessory diductor muscles base, the pair of ventral adductor muscle bases in &a single unit, and dorsal, and the dorsal pedicle adjustor muscle bases not located at the anterior edge of the hinge plate)