Cypridea species (Crustacea, Ostracoda) from the Lower Cretaceous Jinju Formation of the Gyeongsang Basin, South Korea

Based on a large quantity of fossil material and more detailed description of the morphological features, two Cypridea species are recognized from the Jinju Formation of the Gyeongsang Basin: Cypridea jinjuria Choi, 1990 and Cypridea samesi n. sp. These two species do not co-occur and are endemic to South Korea. However, they share the same morphological feature, a swelling/node-like swelling at the anterior cardinal angle area, with some other Cypridea species from the Lower Cretaceous sediments of China and Mongolia. This may suggest a close relationship between these species. Paleobiologically, we infer a parthenogenetic reproduction mode for Cypridea jinjuria Choi, 1990 and Cypridea samesi n. sp., and suggest that the Jinju Formation was deposited under conditions with long hydroperiods.