Takagi 1990. Taxonomic and paleozoogeographic significance of Cenozoic hunch-back like venerids. Part 1. Gigantocallista, gen. nov. (Mollusca: Bivalvia), a new endemic venerid genus from the Pliocene Tatsunokuchi Formation, Sendai City, Miyagi Prefecture, northeastern Japan. Transactions and Proceedings of the Palaeontological Society of Japan New Series, No. 159 1990: 541-553