This is an annelid!
Slyusarev et al. (2022). The structure of the muscular and nervous systems of the orthonectid Rhopalura litoralis (Orthonectida) or what parasitism can do to an annelid. Org Divers Evol 22, 35-45 -- https://doi.org/10.1007/s13127-021-00519-7
@Poppi62 Nice follow up on Gaspar Jekely's reply to Kevin Mitchell ... it is indeed a remarkable development, a great example of how #parasitism can result in greatly simplified organs and body plans in animals such as #annelids.
#DevBio
