Gabonorygma, Antonietto & Carmo & Viviers & Neto & Hunt, 2016

Antonietto, Lucas Silveira, Carmo, Dermeval Aparecido do, Viviers, Marta Claudia, Neto, João Villar Queiroz & Hunt, Gene, 2016, Ostracoda (Arthropoda, Crustacea) from the Riachuelo Formation, Sergipe-Alagoas Basin, Brazil, Upper Aptian-Albian, European Journal of Taxonomy 244, pp. 1-57 : 29

Gabonorygma gen. nov.

urn:lsid:zoobank.org:act:74466CBB-D7CA-4BA8-9749-533416ECBC34

Diagnosis

A genus of Dicrorygmini with the following distinguishing features: sub-rounded to sub-rectangular carapace with rounded, convex dorsal margin, smooth or punctate ornamentation, weakly developed hinge line elements, narrow marginal area and lamellae and valves highly bent inwards in the oral region, sometimes partially obliterating the view of the inner margin and selvage.

Etymology

From the Latin Gabon, meaning “ Gabon ”, a country where specimens of the genus are common in Early Cretaceous strata; and the Greek orygma, meaning “tunnel”, a reference to this genus belonging to the tribe Dicrorygmini Gründel & Kozur, 1975 .

Type species

Dicrorygma (Orthorygma) brotzeni Christensen, 1965 .

Remarks

The tribal and subfamiliar diagnoses follow Gründel (1978b). The Dicrorygmini is a small tribe probably composed by the following genera: Archeocuneocythere Mandelstam, 1947, Dicrorygma Poag Jr, 1965 , Orthorygma Christensen, 1965 (= Oertliana Kilenyi, 1965 ), here raised to the generic level, and Gabonorygma gen. nov. Species of Gabonorygma gen. nov. so far include G. brotzeni (Christensen, 1965) , from the Kimmeridgian–early Tithonian of Denmark, and the presently described G. sergipana gen. et sp. nov. Pattersoncypris ? sp. 1 in Piovesan et al. (2013) is also a species to be included in Gabonorygma gen. nov., if properly reviewed. Cytherideinarum gen. et sp. nov. 2 in Oertli et al. (1961), from the Valanginian–Barremian of Denmark, also belongs to this new genus, although it is not officially described; Cytherideinarum itself cannot be accepted as a valid generic name, as it never received a proper diagnosis. Despite the small number of classified taxa, their number could be considerably larger, since Gabonorygma gen. nov. represents what is in general the most neglected carapace morphology among ostracods, namely, a small, rounded, smooth, mostly featureless general layout.