Trilobita - Ptychopariida - Alokistocaridae
Synonym: Ehmaniellidae Sundberg 1994
Parent taxon: Ptychopariida according to J. C. Lamsdell and P. A. Selden 2015
See also Adrain 2011, Briggs et al. 2008, Sundberg 1994 and Wolfart 1994
Sister taxa: Acrocephalitidae, 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, Norwoodiidae, Olenina, Papyriaspididae, Phylacteridae, Plethopeltidae, Proasaphiscidae, Propeltura, Ptychopariidae, Ptychopariina, Ptychoparoides, Raymondinidae, Shumardiidae, Solenopleuracea, Solenopleuridae, Tricrepicephalidae, Xianquianaspis, Yuehsieszella
Subtaxa: Alokistocare Alokistocarella Altiocculinae Amecephalina Amecephaloides Amecephalus Annamitia Arellanella Beldirella Bythicheilus Chancia Chanciaopsis Danzhaiaspis Ehmania Ehmaniella Ehmaniellinae Elrathia Erdoradites Ganovexopyge Inglefieldia Jenkinsonia Kistocare Lenacare Parapachyaspis Parehmania Pedinocephalina Proveedoria Schopfaspis Shabanovia Tympanuella Utaspis
Ecology: fast-moving low-level epifaunal carnivore
Distribution:
• Cambrian of Antarctica (3 collections), Argentina (6), Canada (55: Alberta-British Columbia, British Columbia, Newfoundland, Northwest Territories, Yukon Territory), China (29), Greenland (8), India (3), Kazakhstan (1), Mexico (3), the Russian Federation (5), the United Kingdom (1), United States (154: Alaska, Arizona, California, California-Nevada, Georgia, Idaho, Idaho/ Utah, Montana, Nevada, Nevada and California, Pennsylvania, Utah, Vermont, Virginia, Wyoming)
• Templetonian of United States (3: Nevada)
• Amgan of the Russian Federation (2), United States (1: Alaska)
• Solvan of Canada (21: British Columbia, Newfoundland and Labrador), Greenland (1), United States (12: Nevada, Pennsylvania)
• Waucoban of Greenland (1)
Total: 309 collections including 435 occurrences