Late Eocene Ostracoda of the Blanche Point Formation, South Australia

Abstract

The Blanche Point Formation (late Eocene) was deposited in the geographically restricted St Vincent Basin, South Australia. The Ostracoda of the Gull Rock and the Perkana Members (of this formation) are characterized by many cytherellids, krithiids, pontocypridids, bythocypridids and many sighted trachyleberidids. These taxa indicate outer shelf or epibathyal depths. Most specimens are represented by single valves, probably mainly as a consequence of the relatively slow sedimentation rate. The basal part of the Gull Rock Member yields a striking dominance of autochthonous cytherellids (synchronous with a peak in dominance of uvigerinid foraminifera) and might perhaps reflect intensification of oxygen minimum conditions. Six new species are proposed: Bairdoppilata willungaensis sp. nov., Trachyleberis maslinensis sp. nov., Trachyleberis reticulopustulosa sp. nov., Actinocythereis? onkaparingaensis sp. nov., Werribeeleberis? mediacosta sp. nov. and Bradleya mypongaensis sp. nov.