Rotifers are multicellular animals that belong to their own distinct ancient phylum (meaning they are morphologically and genetically distinct from other animals at a very fundamental level).

In the early 2000s, molecular data began to show an unexpected amount of genetic diversity in this “phylum of one” (Voigt et al., 2004; Signorovitch et al., 2007; Eitel et al., 2013). Ongoing 16S ...