Brachiopods, crustaceans, vertebrates, and charophytes from the Devonian Ly Hoa, Nam Can and Dong Tho formations of Central Vietnam
Racheboeuf, Patrick
Phuong, Ta Hoa
Hung, Nguyen Huu
Feist, Monique
Janvier, Philippe
Geodiversitas
2006
28
1
5
36
Lyaschenko, 1973
Lyaschenko
1973
[814,1149,1229,1256]
Strophomenata
Chonetidae
Corbicularia
GBIF
Animalia
Strophomenida
20
25
Brachiopoda
genus
TYPESPECIES. — Chonetes menneriLyaschenko, 1958. Frasnian, Russian Platform.
DISCUSSION In the literature, four chonetoidean genera, namely Striatochonetes Mikrjukov, 1968, RhyssochonetesJohnson, 1970, CorbiculariaLyaschenko, 1973, and CeduliaRacheboeuf, 1979, have been defined as including in their diagnosis concentric fila crossing the radial ornament. Ceduliahas already been considered as a junior synonym of Rhyssochonetes( Racheboeuf 1981, 2000). The relationships between Striatochonetes, Rhyssochonetes, and Corbiculariahave also been discussed ( Johnson 1978; Racheboeuf 1981), but the question remained unanswered, mainly because the preservation of the original specimens is different. The former of these three genera, Striatochonetes, was defined with Strophomena setigeraHall, 1843as the typespecies. However Strophomena setigeraexhibits no more than three to four concentric growth lines and lacks the typical concentric fila which are included in the original diagnosis, as established by Johnson (1978), and which are well developed in S. krylovae Mikrjukov, 1968( Mikrjukov 1968: pl. 33, figs 3, 4). The genus name Striatochoneteshas thus to be restricted to the typespecies S. setigeraHall, 1843, until the species is carefully revised. The shell of CorbiculariaLyaschenko, 1973is morphologically very close to that of RhyssochonetesJohnson, 1970, and Johnson (1978: 125)considered that Corbiculariawas a probable junior synonym of Rhyssochonetes. The main difference lies in: 1) a less transverse, more rounded, shell outline in Corbiculariathan in Rhyssochonetes; 2) the orientation of the spines, which are at 45° in Rhyssochonetes, and high-angled to perpendicular in Corbicularia; and 3) the development of a pair of long but faint accessory septa in Corbicularia, at least in the species C. cracoviensisBalinski, 1979. Although the species assigned to Corbicularia, all from the Givetian and Frasnian of the Russian Platform, are poorly known internally, the two genera, Rhyssochonetesand Corbicularia, are here still provisionally regarded as distinct. The species Striatochonetes? parisi Racheboeuf, 1981, and S.? goasquellouensis Racheboeuf, 1981are reassigned to Corbiculariaaccording to their shell size and outline, and high-angled spines.