Diurodrilus is a genus of tiny marine animals that has traditionally been assigned to the annelid worms, although this affinity is not certain.

With a maximum length of 0.45 mm, it has an unusual morphology with many traits not found in other annelids, including a ventral creeping foot.

[1][2] Analyses of DNA have both refuted and supported placement within the annelids,[2][3] with the unusual morphology perhaps due to evolutionary progenesis, in which organisms develop sexual maturity while retaining the larval traits of their ancestors.

[3] The following species are recognised:[2][4]

This annelid-related article is a stub.