Lower Jurassic Ostracod Biozonation of the Mochras Borehole

Abstract. The extensive Lower Jurassic sequence at Mochras has yielded a diverse ostracod fauna which includes many new taxa. Poor preservation precludes a complete taxonomic review of this material although four new species (Cytherella praetoarcensis, Ogmoconcha convexa, Lophodentina striata and Oligocythereis? mochrasensis) are erected herein. Changes in the faunal composition and the rates of faunal turnover are briefly described. An ostracod biozonation is proposed for the section, comparison with established Lower Jurassic zonal schemes reveals that the present section is distinct from most other European sequences.