The Acoela or acoels are a class of small and simple invertebrates in the phylum Xenacoelomorpha that resemble flatworms. Historically they were treated as an order of turbellarian flatworms, but molecular phylogeny studies revealed them to be basal bilaterians.
Species taxanomy provided by GBIF Secretariat (2022). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org on 2023-06-13; License: CC BY 4.0