Brachiopoda : Simplicithyris

Simplicithyris


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

Genus Simplicithyris Zezina, 1976

[Type species= Simplicithyris kurilensis Zezina, 1976 (p. 101)]

Small, smooth, slightly biconvex, recti- marginate to slightly unisulcate; foramen permesothyrid, deltidial plates narrow; pedicle collar broad, dental plates strong; median septum subrectangular; no cardinal process, crura, brachial loop, or spicules. Differs from Amphithyris in possession of dental plates and permesothyrid foramen and from Pumilus in possession of dental plates, smooth inner surface, and lack of spicules.

Present

Diagnosis from volume 6 of the Treatise on Invertebrate Paleontology (2007)

Extant Species of Simplicithyris

S. kurilensis Zezina, 1976

S. japonica (Dall, 1920)
Diagnosis
Diagnosis

FIGURES : Simplicithyris

Geographic distribution

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Simplicithyris kurilensis Zezina, 1976

Type locality: Iturup Island, Kuril, at the depth 16 m (st. 218, sample 511, 1970).
Depth range: 5 - 580 m

Simplicithyris kurilensis Zezina, 1976, p. 102

Diagnosis - Zezina (1976)

in Russian

from Zezina (1979)

Simplicithyris japonica (Dall, 1920)

Type locality: off Hondo (= Honshu), 119 m
Depth range: 119 m

Platidia japonica Dall, 1920, p. 333.
Simplicithyris japonica: Zezina (1976)

Diagnosis (Dall,1920)
Shell resembling Platidia seminula but much larger, the valves when normally developed relatively wider, the foramen entirely confined to the attached valve, the free valve having the apex entire and a very narrow long fiattish area on each side ; the soft parts, so far as could be determined from a dry specimen softened in weak liquor potassae, do not differ in arrangement from the Mediterranean species.


Simplicithyris kurilensis Zezina, 1976 Type locality: Iturup Island, Kuril, at the depth 16 m (st. 218, sample 511, 1970). Depth range: 5 - 580 m Simplicithyris kurilensis Zezina, 1976, p. 102 Diagnosis - Zezina (1976) in Russian	from Zezina (1979)

Simplicithyris japonica (Dall, 1920) Type locality: off Hondo (= Honshu), 119 m Depth range: 119 m Platidia japonica Dall, 1920, p. 333. Simplicithyris japonica: Zezina (1976) Diagnosis (Dall,1920) Shell resembling Platidia seminula but much larger, the valves when normally developed relatively wider, the foramen entirely confined to the attached valve, the free valve having the apex entire and a very narrow long fiattish area on each side ; the soft parts, so far as could be determined from a dry specimen softened in weak liquor potassae, do not differ in arrangement from the Mediterranean species.