Even though the ostracod-like fossils that occur in Cambrian rocks are now excluded from the Ostracoda as strictly construed, they are included in the present volume to complete the stratigraphical record of such animals in British rocks. These Cambrian ostracod-like forms are currently referred to the orders Bradoriida Raymond, 1935 and Phosphato-copida Müller, 1964. Originally Raymond (1935) established the Order Bradorina (sic) to include all Cambrian ostracod-like forms. Muller (1964) subdivided the Bradoriida into the suborders Phosphatocopina, which he consided to have primary phosphatic carapaces, and Bradoriina, supposedly with chitinous or calcareous carapaces. In 1982 Müller raised both these groups to ordinal level; such a classification based on carapace composition is, however, untenable (Siveter & Williams 1997). Phosphatocopids were first considered to be early ostracods (Muller 1964, 1979; Jones & McKenzie 1980), but, based on more recent evidence from soft parts, they are now known to be the sister group of the Eucrustacea (Walossek 1999; Siveter et al. 2001, 2003; Maas et al. 2003). The Bradoriida (sensuMuller 1982) are probably a polyphyletic group that may include ancestral ostracods together with other crustacean or arthropod groups (Jones & McKenzie 1980; Hou et al. 1996). Hinz-Schallreuter (1993b, 1998, 2000), who preferred to encompass both bradoriids and phosphatocopids under the name ‘Archaeocopa’ (ex Archaeocopida Sylvester-Bradley, 1961), characterized the order as an 'ostracod group' distinct from 'true ostracods' by
Figures & Tables
This book charts the stratigraphical distribution of ostracods in the Cambrian to Pleistocene deposits of Britain and outlines their utility for dating and correlating rock sequences, as well as indicating aspects of their palaeoenvironmental and palaeogeographical significance. These small bivalved crustaceans are the most abundant arthropods in the fossil record. Indeed, the stratigraphy of Britain, which embraces many type-sequences, provides a particularly rich and full record of them, from at least the basal Ordovician, and from the British Cambrian there is a biostratigraphy based on their ‘relatives’, the bradoriids and phosphatocopids. Ostracod distributions demonstrate the ecological success story of the group, occupying as they do marine, non-marine and even ‘terrestrial’ habitats. Written by current specialists in the field, this book is an authoritative account and will be welcomed by all micropalaeontologists and applied geologists in the industrial and academic world alike. It is richly illustrated with over 80 plates of electron micrographs and specially drawn maps, diagrams and range-charts.