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The revision of Theriosynoecum Branson 1936, a common ostracod genus of Middle Jurassic to Early Cretaceous nonmarine deposits worldwide, demonstrates that its representatives–particularly the Early Cretaceous North American ones–are not as endemic as hitherto assumed. The taxonomic concept applied herein resolves many problems resulting from an overestimation of the taxonomic (in-)significance of some ornamentation elements in the genus as well as the too regional view of the faunas during the second half of the 20th century. This is the first step to a supraregional biostratigraphic and improved paleoecologic application of representatives of the extinct genus Theriosynoecum (Cytheroidea, Limnocytheridae, Timiriaseviinae). Theriosynoecum fittoni (Mantell 1844) and Theriosynoecum alleni (Pinto and Sanguinetti 1962) are proposed for being synonymous because of their many striking similarities. The species Theriosynoecum forbesii (Jones 1885) and T. verrucosa (Jones 1885) are considered separate and not subspecies of T. forbesii. Theriosynoecum verrucosa occurs in the uppermost Morrison Formation of the Black Hills area, South Dakota, U.S.A., Theriosynoecum fittoni in the Lakota Formation of the same area. Theriosynoecum pahasapensis (Roth 1933) is, thus far, endemic to North America. A key to the described species is presented. Early Cretaceous species of Theriosynoecum are not yet as applicable biostratigraphically in North America as in Europe (e.g. the English Purbeck/Wealden), but this is due to the lack of data from the former area and considered to be promising once more data are available. Nevertheless, the "classic" taxonomic approach provides a considerable step towards better application of these taxa as well as future analysis and robust discussion regarding the phylogeny, evolution and distribution of the limnocytherid subfamily Timiriaseviinae. The genus Metacypris is now restricted to an Aptian to recent lineage of small, weakly monosulcate Timiriaseviinae. Middle Jurassic to Early Cretaceous bisulcate and large taxa formerly designated as Metacypris are now assigned to Theriosynoecum.

Despite the fact that the number of publications on the morphologic terms of ostracod carapace features is impressive, definitions, use and interpretation of many terms remain inconsistent and therefore fraught with problems. A particular problem is the application of certain terms of morphologic features in different ostracod groups without the consideration of their potentially different origin, genesis and nature. This revised and annotated glossary focuses on nonmarine ostracods, families Timiriaseviinae (Cytheroidea, Limnocytheridae) and Cyprideidae (extinct, Cypridoidea), particularly on the extinct genera Theriosynoecum and Cypridea in its selection of terms and given examples, and is strongly connected with the preceding papers of this issue (Sames 2011a, b) which also include the supporting illustrations. It as well comprises detailed discussions on the origin and differentiation of the taxonomic or otherwise significance of selected carapace features, particularly ornamentation. Herein, ornamentation is subdivided into area-wide and local ornamentation elements for that reason. In contrast to their patterns of distribution, the presence of local ornamentation elements as well as their degree of expression are considered of no, or rather low, taxonomic significance. If applicable, local ornamentation elements can be used for paleoenvironmental interpretations or to identify juveniles in some cases (e.g. in Cypridea). Type, occurrence and shape of area-wide ornamentation elements are, by contrast, always taxonomically relevant to a certain degree. As to the Family Cyprideidae, the alveolar ridge is newly introduced and defined, and the terms for the anteroventral (alveolus and its elements) and posteroventral regions (cyathus, cyathus-like protrusion) are redefined and discussed. A morphologic term can never be a matter of common or collective knowledge as long as its appreciation and usage differs between researchers. In fact, the accuracy of its usage can only be identified when we know that we are talking about the same thing. With this glossary it is intended to better communicate the views of the author, to integrate new insights into ostracod paleobiology into the interpretation of carapace features, and to propose a kind of harmonization between different concepts as well as to put these up for discussion and further development.

Cypridea Bosquet 1852 (Cypridoidea, Cyprideidae) is a Kimmeridgian to Lower Eocene nonmarine ostracod genus, the representatives of which are very common and stratigraphically useful in Late Tithonian to earliest Barremian "Purbeck/Wealden-like" nonmarine deposits of the world. The revision of particularly North American representatives led to progress in its taxonomy, and a breakthrough in its biostratigraphic supraregional biostratigraphic application. Key to their successful application is an upgraded taxonomic concept including new insights into the coherences of specific reproductive mechanisms (asexual and mixed reproduction) in the context with diversity and dispersal modes, combined with the understanding and evidence that these ostracods are not as endemic as erstwhile believed. This taxonomic concept resolves crucial problems resulting from an overestimation of the taxonomic significance of several carapace characters (particularly ornamentation elements and the outline), and facilitates improved stratigraphic and paleoecologic applications as well as providing the basis for further research. The revision includes an extensive historic overview of most relevant publications. Representatives of Cypridea have great utility in improving the biostratigraphic age determination for and correlation of Early Cretaceous formations of the Western Interior foreland basin. With respect to suprageneric taxonomy, the family Cyprideidae Martin 1940 is partially revised as well. Longispinella Sohn 1979 is now considered a subgenus of Cypridea while Cypridea (Guangdongia) Guan 1978 is allocated to Bisulcocypridea Sohn 1969, and the genus Praecypridea Sames, Whatley and Schudack 2010(b) is included. The genus Cypridea is emended anew. As for the subgeneric taxonomy, the North American species Cypridea (Pseudocypridina) inornata (Peck 1951) is now considered a junior synonym of Cypridea (P.) setina (Anderson 1939), Cypridea (P.) laeli Sohn 1979 considered an ecophenotype of Cypridea (P.) piedmonti (Roth 1933), and Cypridea (Longispinella) asymmetrica Sohn 1979 designated synonymous (sexual dimorph) to C. (L.) longispina Peck 1941. Sexual dimorphism is presumed in several species of Cypridea and mixed reproduction corroborated as being the most likely reproductive mechanism among taxa of this genus. Cypridea? minuta (Peck 1951) most probably represents an early representative of the sulcate Bisulcocypridea Sohn. Ostracod correlations mainly based on representatives of Cypridea strongly suggest a much higher maximum age for some Lower Cretaceous formations (Lakota Formation, South Dakota and Wyoming, and Cedar Mountain Formation, Utah) of the Western Interior foreland basin, i.e., Berriasian to Early Valanginian instead of Barremian or Aptian.

Introductory Note