Monotypic prehistoric annelid genera

Burgessochaeta is an extinct genus of polychaete annelids from the Middle Cambrian. Its fossils have been found in the Burgess Shale in British Columbia, Canada. The genus was described by Conway Morris (1979) and re-examined by Eibye-Jacobsen (2004).

Websteroprion ("Webster's saw") is a genus of eunicidan polychaete that lived during the middle Devonian period in what is now Canada. It contains a single species, W. armstrongi, recovered from the Kwataboahegan Formation.