[1] Univ Cape Town, Marine Res Inst, Private Bag X3, ZA-7701 Rondebosch, South Africa
[2] Univ Cape Town, Dept Geol Sci, Private Bag X3, ZA-7701 Rondebosch, South Africa
[3] Univ Cape Town, Dept Environm & Geog Sci, Private Bag X3, ZA-7701 Rondebosch, South Africa
[4] Iziko South African Museum, Invertebrate Palaeontol & Geol, POB 61, ZA-8000 Cape Town, South Africa