For the first time, soft body parts of ostracod genera, Nipponocythere Ishizaki, 1971 from the family Loxoconchidae and Ambtonia Malz, 1982 from the family Trachyleberididae, both belonging to the superfamily Cytheroidea, are described and illustrated. The specimens are male representatives of the species Nipponocythere bicarinata (Brady, 1880) and Ambtonia obai (Ishizaki, 1971), collected from Wando Island, Korea. Their soft body morphology does not completely conform with the latest identification key to cytheroid families, which suggests the need for a comprehensive revision. A revised diagnosis for the type species of both genera, Nipponocythere asamushiensis Ishizaki, 1971 and Ambtonia glabra Malz, 1982 is given. Stratigraphic ranges and ecological and paleoecological significance of families Loxoconchidae and Trachyleberididae are being discussed. Published records of N. bicarinata that provide an illustration and/or SEM have been taxonomically reviewed and a list of morphological variations is given. Spatial distribution data for both target species, N. bicarinata and A. obai, as well as their respective genera, were compiled separated by time: recent (i.e., Holocene) versus fossil (older than Holocene). With respect to the detected eco-phenotypes of N. bicarinata, a re-evaluation of its spatial distribution is given. We found that by excluding these morphological variations, its assumed spatial distribution is significantly altered, shifting its southernmost distribution margin, previously reported from the South China Sea, north to the northernmost region of the East China Sea.

首次描述和说明了介形虫属的软体部分，1971 年来自 Loxoconchidae 家族和Ambtonia Malz，1982 年来自Trachyleberididae家族，都属于 Cytheroidea 超科。这些标本是从韩国莞岛采集的Nipponocythere bicarinata (Brady, 1880) 和Ambtonia obai (Ishizaki, 1971)的雄性代表。它们的软体形态不完全符合最新的cytheroid家族鉴定密钥，这表明需要进行全面修订。两种属的模式种的修订诊断，Nipponocythere asamushiensis Ishizaki，1971 年和Ambtonia glabra Malz，1982 年给出。正在讨论Loxoconchidae和Trachyleberididae科的地层范围和生态学和古生态学意义。提供插图和/或 SEM 的已发表的N. bicarinata记录已经过分类审查，并给出了形态变异列表。目标物种N. bicarinata和A. obai以及它们各自属的空间分布数据按时间分开编制：最近（即全新世）与化石（比全新世更早）。对检测到的双头猪笼草的生态表型，对其空间分布进行了重新评估。我们发现，通过排除这些形态变化，其假设的空间分布发生了显着变化，将其最南端的分布边缘（先前报道的从南海向北转移到东海最北端）。