†Sekwicyathus nahanniensis Handfield 1971 (sponge)
Full reference: R. C. Handfield. 1971. Archaeocyatha from the MacKenzie and Cassiar Mountains, Northwest Territories, Yukon Territory and British Columbia. Geological Survey of Canada Bulletin 201:1-119
Belongs to Sekwicyathus according to R. C. Handfield 1971
Sister taxon: Sekwicyathus polygonalis
Type specimen: GSC #25317
Ecology: stationary intermediate-level epifaunal suspension feeder