Copytus, Skogsberg, 1939

Coimbra, João Carlos, Bergue, Cristianini Trescastro & Ramos, Maria Inês Feijó, 2020, Is Copytus Skogsberg, 1939 (Crustacea: Ostracoda) a neocytherideid? With description of a new family and two new species, Zootaxa 4729 (2), pp. 177-194 : 179

Is Copytus a neocytherideid?

Puri (1952) erected Cytherideisinae as new subfamily of Cytherideidae , based on the genus Cytherideis Jones, 1856 , and joining also Copytus Skogsberg 1939 , Pontocythere Dubovsky 1939 , Krithe Brady, Crosskey & Robertson 1874 , Cushmanidea Blake 1933 , Sahnia Puri 1952 , and Neocytherideis Puri 1952 . Sylvester-Bradley & Harding (1953), based on a recommendation of the International Commission on Zoological Nomenclature, changed the name of this subfamily to Cytherideidinae. However, in the same publication, they considered Cytherideis a junior synonym of Cypridea Bosquet, 1852 , a genus of the subfamily Cyprideinae Martin, 1940 . For that reason, Puri (1957) changed the name of the subfamily proposed by himself in 1952, to Neocytherideinae with Neocytherideis Puri, 1952 being the nominate genus. Hartmann & Puri (1974) raised this subfamily to full family status, which is considered appropriate for most ostracodologists.

Athersuch et al. (1989) presented a diagnosis for Neocytherideidae , where the hinge is lophodont and the adductor scars composed of a somewhat oblique or curved row of four imprints. In fact, genera indisputably attributed to Neocytherideidae , i.e., Neocytherideis Puri, 1952 , Procytherideis Ruggieri, 1978 , Sahnicythere Athersuch, 1982 (for Sahnia Puri, 1952 ) and Papillosacythere Whatley, Chadwick, Coxill & Toy, 1987 , show hinge and adductor scars in accordance to Athersuch et al. (1989). The appendages of this family, as also described by Athersuch et al. (1989), are similar in all genera. The hemipenis morphology, especially the distal process shape, varies among species of the same genus. This is the reason why they did not consider soft parts in the generic taxonomy of Neocytherideidae .

Copytus , besides other minor differences, has (i) a proportionally longer hinge line, not confined to the posterior half of the length, as typical of most species of Neocytherideidae , and (ii) bears a small rounded group of four adductor scars, which differ from the somewhat oblique or curved vertical row of the neocytherideids. We understand that the hinge and central muscle scars of this genus distinguish it from all other Neocytherideidae , and therefore a new family is herein proposed to hold the species of Copytus (see chapter ‘Taxonomy’).