Taxonomy of deep-sea trachyleberidid, thaerocytherid, and hemicytherid genera (Ostracoda)

Abstract

We conducted a comprehensive systematic revision of deep-sea Trachyleberididae, Thaerocytheridae, and Hemicytheridae (Ostracoda, Crustacea) covering almost all Cenozoic genera using high-resolution scanning electron microscopy. Trachyleberididae, our main focus, is one of the most diverse and abundant ostracod families, but its genus-level taxonomy is still confusing. Approximately 700 specimens from 177 species from 47 genera were examined. The studied samples range in age from the Cretaceous to the present day and cover all major oceans in the world including Atlantic, Pacific, Indian, and Southern Oceans, Mediterranean Sea, and Gulf of Mexico. Five new genera and 45 new species are described. Emended concepts are proposed for several important genera to better stabilize their taxonomy. This study considerably reduces taxonomic uncertainty of this important component of the modern and fossil deep-sea ostracod community and provides a robust taxonomic baseline for deep-sea ostracod-based paleoceanographic, paleoecological, and macroevolutionary research.