†family Dolichometopidae Walcott 1916
This has gotten effed up because the eponymous subfamily was entered later, with subsequent opinions elevating it to a family. So, it's now cut off from everything.
Full reference: C.D. Walcott. 1916. Cambrian geology and paleontology III. No. 5. Cambrian trilobites. Smithsonian Miscellaneous Collections 64:303-456
Sister taxa: none
Subtaxa: none
Distribution:
• Cambrian of Canada (14: Northwest Territory collections), New Zealand (1)
Total: 15 collections including 19 occurrences