Saxipendiidae Harrimaniidae is a basal family of acorn worms.

A taxonomic revision was undertaken in 2010, and a number of new genera and species found in the Eastern Pacific were described.

[1] In this family the development is direct without tornaria larva, and circular muscle fibers in their trunk is missing.

[2] There is some indication that Stereobalanus may be a separate basal acorn worm lineage, sister to all remaining acorn worms.

[3] The following genera and species are listed in the World Register of Marine Species:[4] This hemichordate-related article is a stub.