Brachiopoda : Joania

Joania

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

Genus Joania Alvarez, Brunton & Long, 2008

[Type-species = Terebratula cordata Risso, 1826 p. 389]

Megathiridid genus with relatively small adult size, outline varying from elongate heart-shaped to rounded subrectangular, with narrow hinge, profile biconvex to ventribiconvex; externally two to four rounded and weakly defined ribs; dorsal interior with strong trifid, short-shafted cardinal process; median septum with tuberculate antero-ventral edge; radial ridges with well defined tubercles submarginally, anterior to weakly defined descending lamellae of brachidium, raised only posteriorly and at edges of median septum.

Eocene - Recent

Diagnosis from Alvarez et al. (2008)

Species of Joania

J. cordata (Risso, 1826)

J. arguta Grant, 1983

Argyrotheca mayi Blochmann, 1914 - perhaps belonging to Joania

Argyrotheca anomala Cooper, 1983: Late Eocene - perhaps belonging to Joania

Diagnosis
Diagnosis

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Joania cordata (Risso, 1826)

Type locality: off Nizza, Mediterranean coast.
Depth range: 3 - 600 m

Terebratula neapolitana Scacchi, 1833
Orthis neapolitana (Scacchi) : Philippi (1844)
Argiope neapolitana (Scacchi) : Davidson, 1852)
Argiope Forbesii (Scacchi) : Davidson (1852)
Terabratula (Argiope) neapolitana (Scacchi) : Reeve (1861)
Argiope biplicata Seguenza, 1876
Argiope kowalevskii Schulgin, 1885
Cistella neapolitana (Scacchi) : Davidson (1887)
Argyrotheca cordata (Risso) : Dall (1920)
Joania cordata (Risso) : Alvarez, Brunton & Long (2008)

Diagnosis - Risso (1826)

T. Testa glaberrima, cordata, lucida ; valvis ambabus punctulis albis impressis sculptis ; epidermide fulvescente pellucida.

Coq. très lisse, cordée, luisante; à valves sculptées de très petits points blancs; l'épiderme est d'un brunâtre translucide. Long. 0,005. Séj. Régions coralligènes. App. Printemps, été.

Joania arguta (Grant, 1983)

Type locality: "underside of coral frond from USNM loc. 32014 on the lagoon side of Igurin Island, Enewetak Atoll, depth 14 m".
Depth range: 14 - 100 m.

Argyrotheca arguta Grant, 1983, p. 178
Argyrotheca sp. Cooper, 1954
Argyrotheca arguta: Alvarez, Brunton & Long (2008)
? Argyrotheca sp. Bitner, 2008

Diagnosis from Simon (2010)

Shell dorsibiconvex, small, known width less than three mm; white or translucent or light tan most lacking costae; outline variable from subquadrate to heart-shaped, subpentagonal with emarginated anterior margin. Hinge line straight, nanower than the shell. Ventral valve with a microtuberculate external shell surface. Ventral valve with apical angle around 124°-131°; large pedicle collar; robust teeth given offdorsally; low blade-like ventral median septum; valve floor with radial ridges terminating in tubercles near the anterior margin. Dorsal valve with median sulcus producing a slightly sulcate anterior commissure; strong, deep sockets with elevated inner socket ridges; complex strong cardinal process; strong triangular senate dorsal septum; valve floor with radial ridges terminating in marginal tubercles; loop circling laterally with short pointed crural processes, descending branches weakly defined fused rapidly with valve floor and attached to lateral sides of dorsal septum. Shell coarsely punctate with 250/280 punctae/mm².


Joania cordata (Risso, 1826) Type locality: off Nizza, Mediterranean coast. Depth range: 3 - 600 m Terebratula neapolitana Scacchi, 1833 Orthis neapolitana (Scacchi) : Philippi (1844) Argiope neapolitana (Scacchi) : Davidson, 1852) Argiope Forbesii (Scacchi) : Davidson (1852) Terabratula (Argiope) neapolitana (Scacchi) : Reeve (1861) Argiope biplicata Seguenza, 1876 Argiope kowalevskii Schulgin, 1885 Cistella neapolitana (Scacchi) : Davidson (1887) Argyrotheca cordata (Risso) : Dall (1920) Joania cordata (Risso) : Alvarez, Brunton & Long (2008) Diagnosis - Risso (1826) T. Testa glaberrima, cordata, lucida ; valvis ambabus punctulis albis impressis sculptis ; epidermide fulvescente pellucida. Coq. très lisse, cordée, luisante; à valves sculptées de très petits points blancs; l'épiderme est d'un brunâtre translucide. Long. 0,005. Séj. Régions coralligènes. App. Printemps, été.

Joania arguta (Grant, 1983) Type locality: "underside of coral frond from USNM loc. 32014 on the lagoon side of Igurin Island, Enewetak Atoll, depth 14 m". Depth range: 14 - 100 m. Argyrotheca arguta Grant, 1983, p. 178 Argyrotheca sp. Cooper, 1954 Argyrotheca arguta: Alvarez, Brunton & Long (2008) ? Argyrotheca sp. Bitner, 2008 Diagnosis from Simon (2010) Shell dorsibiconvex, small, known width less than three mm; white or translucent or light tan most lacking costae; outline variable from subquadrate to heart-shaped, subpentagonal with emarginated anterior margin. Hinge line straight, nanower than the shell. Ventral valve with a microtuberculate external shell surface. Ventral valve with apical angle around 124°-131°; large pedicle collar; robust teeth given offdorsally; low blade-like ventral median septum; valve floor with radial ridges terminating in tubercles near the anterior margin. Dorsal valve with median sulcus producing a slightly sulcate anterior commissure; strong, deep sockets with elevated inner socket ridges; complex strong cardinal process; strong triangular senate dorsal septum; valve floor with radial ridges terminating in marginal tubercles; loop circling laterally with short pointed crural processes, descending branches weakly defined fused rapidly with valve floor and attached to lateral sides of dorsal septum. Shell coarsely punctate with 250/280 punctae/mm².