Class Enteropneusta (acorn worm)
Parent taxon: Hemichordata according to C. B. Cameron 2016
See also Bulman 1970, Nielsen 2012, Sepkoski 2002 and Zrzavy et al. 1998
Sister taxon: Pterobranchia
Subtaxa: Harrimaniidae Oesia Spartobranchus Spengelidae
Distribution:
• Jurassic of Italy (1 collection)
• Carboniferous of United States (2: Illinois)
• Cambrian of Canada (24: British Columbia), China (1), the Russian Federation (1), United States (12: California, Idaho, Pennsylvania, Utah)
Total: 41 collections including 46 occurrences