Trilobita - Ptychopariida - Norwoodiidae
Parent taxon: Ptychopariida according to H. B. Whittington et al. 1997
See also Adrain 2011
Sister taxa: Acrocephalitidae, Alokistocaridae, Amphorella, Atratebiinae, Bifodina, Bolaspididae, Bulnibarbi, Bvalbardites, Catillicephalidae, Chondrastaulina, Chuangiformis, Cliffiidae, Conococheaquea, Conocoryphidae, Conokephalinidae, Crepicephalidae, Diceratocephalidae, Elviniidae, Harpina, Indiligens, Kazelina, Kingstoniidae, Kirengelia, Lisaniidae, Lonchocephalidae, Lorenzellidae, Marjumiidae, Meniscocorphye, Meniscocoryphe, Menomoniidae, Neoanomocerella, Olenina, Papyriaspididae, Phylacteridae, Plethopeltidae, Proasaphiscidae, Propeltura, Ptychopariidae, Ptychopariina, Ptychoparoides, Raymondinidae, Shumardiidae, Solenopleuracea, Solenopleuridae, Tricrepicephalidae, Xianquianaspis, Yuehsieszella
Subtaxa: Cedaraspis Hardyoides Holcacephalus Levisaspis Norwoodella Norwoodia Paranorwoodia
Ecology: fast-moving low-level epifaunal suspension feeder
Distribution:
• Ordovician of Canada (2: Newfoundland and Labrador collections), United States (1: Vermont)
• Taoyuanian of China (2)
• Cambrian of Argentina (2), Canada (10: Newfoundland, Newfoundland and Labrador, Quebec, Yukon), China (1), Kazakhstan (19), the Russian Federation (2), United States (28: Alaska, Georgia, Nevada, South Dakota, Texas, Utah, Virginia, Wisconsin, Wyoming)
Total: 67 collections including 70 occurrences