Phylogenetic assessment of endangered and look-alike Pigtoe species in a freshwater mussel diversity hotspot.

The Green River in Kentucky in the eastern United States is a freshwater mussel biodiversity hotspot, with 71 known species. Among them, the endangered coexists with other morphologically similar species in the genera and , known colloquially as "pigtoes." Identification of species in these genera is challenging even for mussel experts familiar with them.