Figure 1 in Palaeoheterodont diversity (Mollusca: Trigonioida + Unionoida): what we know and what we wish we knew about freshwater mussel evolution

Figure 1. Taxonomic and geographical diversity of the Unionoida. Data summarized from Table 1. A, Taxonomic partitions of the Unionoida. Separate wedges represent the two superfamilies discussed in the text: Unionoidea and Etherioidea. B, Geographical distribution of the Unionoida. The smaller wedge represents the southern continents: South America, Africa, and Australasia.