Ostracoda from the Kimmeridge Clay Formation (Upper Jurassic) of the North Wootton Borehole was examined from a biostratigraphical point of view. The ostracod zonal scheme, previously erected for the stratotype section in Dorset, is modified and the faunas are related to the 47 beds which can be recognised by a combination of macrofaunal and lithological characteristics. Seven ostracod assemblage zones are recognised in the borehole, of these three are new and one is subdivided into two subzones. One new genus, Micrommatocythere, together with four new species and one new subspecies–Micrommatocythere edmundi, Paranotacythere (Unicosta) effusa, Mandelstamia (Xeromandelstamia) horrida, Macrodentina (Polydentina) woottonensis and Galliaecytheridea mandelstami kilenyii–are described.
- © 1983 The Micropalaeontological Society