Electrocypria, Wang & Matzke-Karasz & Horne, 2022

Wang, He, Matzke-Karasz, Renate & Horne, David J., 2022, Mid-Cretaceous coastal amber forest palaeoenvironment revealed by exceptionally preserved ostracods from an extant lineage, Fossil Record 25 (1), pp. 147-172 : 147

Electrocypria gen. nov.

Type species.

Electrocypria burmitei sp. nov.

Etymology.

Name referring to ‘electrum’, the Latin term for amber + cypria, a common epithet in candonid ostracods.

Diagnosis.

Small ostracods of the family Candonidae , with subrectangular (male) to trapezoidal (female) lateral carapace shape. Dorsal margin with greatest height at about 1/3rd of length, tapering down in straight line from there towards anterior and posterior ends. Anterior end curved broadly, posterior end with narrow curve, but not pointed. Calcified inner lamella not broad. Female higher than male. Fusiform in dorsal view with greatest width at mid-length. A1 with segments 3 to 8 separate (not fused). Natatory setae present on A2. L7 with segments 3 and 4 clearly separate, each without dorso-apical, marginal spiny processes (hooks). Terminal segment short (not longer than wide), carrying a robust and long claw h2 and a long reflexed seta h3. UR with anterior and posterior claws of the same length.

Remarks.

The new genus is excluded from the Ilyocyprididae and Notodromadidae by its carapace morphology, and from the most Cyprididae subfamilies by its lack of a terminal pincer on the L7 (see, e.g., Horne et al. 2019). We are aware of some extant cypridid genera of the subfamily Cypridopsinae with non-pincer L7 (e.g., Neocypridopsis Klie, 1940; Paranadopsis Almeida et al., 2021; Cyprettadopsis Savatenalinton, 2020) or incomplete pincer structure (e.g., Brasilodopsis Almeida et al., 2021) but all of these share the cypridopsine character of a reduced UR, unlike Electrocypria which has a fully developed UR. There is also the genus Batucypretta (subfamily Batucyprettinae ) with a much reduced UR and lacking the L7 pincer, considered by its describing authors ( Victor and Fernando 1981) to be transitional to the Cypridopsinae . The cyprid genus Zonocypretta De Deckker, 1981 (subfamily Bradycypridinae ) lacks the L7 pincer and has a fully-developed UR, but differs from Electrocypria by virtue of other features including marginal septa in the valves.

Within the three subfamilies of the Candonidae , Electrocypria is best allocated to the Paracypridinae , foremost because of the natatory setae observed in the female specimen. Such natatory setae are not present in the Candoninae . The third subfamily, Cyclocypridinae , can be excluded by the valve morphology and shape, as well as by the cyclocypridine L7 morphology with segments 3 and 4 being fused, and the terminal segment carrying a long reflexed seta h3 and two short h1 and h2 setae distally. The genus Electrocypria therefore belongs to the subfamily Paracypridinae , which is currently subdivided into three tribes, these being the marine Paracypridini and the marine to brackish Thalassocypridini and Renaudcypridini . Although the carapace morphology may point to the Thalassocypridini , Electrocypria cannot be allocated to this tribe because of its L7 morphology, with segments 3 and 4 not being fused, a short terminal segment and its two long h setae distally. In the Thalassocypridini , segments 3 and 4 of L7 are fused, the terminal segment is long and bears only a long reflexed seta, while the other two h setae are short. Electrocypria does not qualify as a Renaudcypridini because of the lack of a unique feature of this tribe: the strong, spiny processes situated dorso-distally on both segments 3 and 4 of L7. In Electrocypria the dorsal edges of these segments are clearly smooth. Also, Renaudcypridini possess a well-developed tooth in the antero-ventral area of the inner lamella in the LV, complemented by a defined socket on the inner lamella of the RV ( Wouters 2001) - characters that could not be observed in Electrocypria . Species of the third tribe, Paracypridini , typically show wide calcified inner lamellae with narrow vestibula and broad fused zones with radial pore canals in their well-calcified carapaces. These characters are not present in Electrocypria . The genera of the Paracypridini are more diverse in their soft body features than those of the Thalassocypridini and Renaudcypridini , as shown in the detailed review of anatomical features in the Paracypridinae by Maddocks (1992). The anatomy of A1 with its varying degrees of segment fusion and the variable combination of L7 features in the different genera may serve as examples. However, none of these mosaic patterns of characteristics fits to those observed in the type species of Electrocypria . Due to the valve morphology, combined with the lack of congruence in important soft body features with any genus of the Paracypridini , we refrain from attributing Electrocypria to this tribe. Consequently, we cannot allocate the genus Electrocypria to any of the currently accepted three tribes of the Paracypridinae .