Palaeozoic Ostracoda: The standard classification scheme

In this contribution to "Palaeozoic Ostracod Classification", the systematic framework adopted in the POC series is reviewed. This classification scheme, initially developed for the new ostracod Treatise ("Treatise on Invertebrate Paleontology, Pt. Q, Ostracoda, Revised" [TPO]), was first announced as a new Treatise standard by WHATLEY et al. (1993). Following a proposal previously made by the present writer, it was subsequently (by Treatise Authors' authority) cleared of taxonomical and nomenclatural ballast. For POC, emphasis is put on orders essentially dealt with in these series, namely Palaeocopida HENNINGSMOEN, 1953 (including suborders Palaeocopina HENNINGSMOEN, 1953 and Platycopina SARS, 1866.) and (Palaeozoic) Podocopida SARS, 1866 (including suborders Metacopina SYLVESTER-BRADLEY, 1961 and Podocopina SARS, 1866). Key reviews are presented concerning the following subjects: "pseudo-advanced" structures ("infold-like" features, pseudo-cytherellid muscle field), kirkbyaccan key characters, kloedenellid dimorphism instead of "domatial" domiciliar dimorphism, as well as modern terminology (adductor muscle scar patterns, dimorphic extradomiciliar structures); and the concept of "evolutionary dead-ends" is explained. In an Appendix, specifically literature relevant problem cases are reviewed, with special reference to questions concerning assumed palaeocopine offshoots.