Article: Occurrence of the bivalve genus Manticula in the Early Cretaceous of Antarctica

A new occurrence of a pergamidiid bivalve genus, which can probably be assigned to Manticula Waterhouse, 1960, is established within the Early Cretaceous (Berriasian) of Antarctica. Such a record is of particular interest as this taxon was only known previously from the Late Triassic of New Zealand and New Caledonia. The Antarctic material is contained within a new species, M. complanata, which is shown to be somewhat smaller and less inflated than the genotypic M. problematical (Zittel). There are indications from the Antarctic species that, at least in juvenile specimens, the hinge region of the left valve is characterized by a prominent saddle-shaped fold (or tooth) and a triangular resilifer. Using features such as these and details of the shell structure, it is possible to establish close links between Manticula and the pergamidiid genus Krumbeckiella on the one hand, and the eurydesmid genus Eurydesma on the other. The eurydesmid-pergamidiid group is essentially a Southern Hemisphere one with high-latitude origins in the Early Permian. Following a phase of expansion through the Triassic, it would appear to have retracted to the single Antarctic occurrence of Manticula in the Early Cretaceous.