Pterobranchia - Graptoloidea - Dichograptidae
Technically ranked as a "section" grade, but ranking as subfamily because below family rank.
Full reference: O. M. B. Bulman. 1970. Graptolithina with sections on Enteropneusta and Pterobranchia (Second edition, revised and enlarged). Treatise on Invertebrate Paleontology V:V1-V163
Parent taxon: Dichograptidae according to O. M. B. Bulman 1970
Sister taxa: Clonograptus, Dichograpti, Dichograptinae, Dichograptus, Didymograptus, Goniograpti, Loganograptus, Orthodichograptus, Schizograpti, Temnograpti, Tetragrapti
Subtaxa: Atopograptus Azygograptus Janograptus Maeandrograptus Oncograptus Parazygograptus Skiagraptus
Ecology: passively mobile planktonic suspension feeder
Distribution:
• Whiterockian of Canada (2: Newfoundland and Labrador collections), United States (1: Texas)
• Arenig of Bolivia (1), China (16), Morocco (1), Sweden (1)
• Ningkuo of China (8)
• Dawan of China (3)
• Ordovician of Argentina (4), Bolivia (1), China (5), Czechia (1), Lithuania (2), Morocco (1), New Zealand (13), Norway (2), Spain (1), United States (1: Idaho)
Total: 64 collections including 72 occurrences