Trilobita - Ptychopariida - Tricrepicephalidae
Full reference: A. R. Palmer. 1954. The Faunas of the Riley Formation in Central Texas. Journal of Paleontology 28(6):709-786
Parent taxon: Ptychopariida according to J. C. Lamsdell and P. A. Selden 2015
See also Adrain 2011 and Jell and Adrain 2002
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, Norwoodiidae, Olenina, Papyriaspididae, Phylacteridae, Plethopeltidae, Proasaphiscidae, Propeltura, Ptychopariidae, Ptychopariina, Ptychoparoides, Raymondinidae, Shumardiidae, Solenopleuracea, Solenopleuridae, Xianquianaspis, Yuehsieszella
Subtaxa: Erediaspis Meteoraspis Tricrepicephalus
Type: Tricrepicephalus
Ecology: fast-moving low-level epifaunal carnivore
Distribution:
• Cambrian of Argentina (1 collection), Australia (1), Canada (12: Newfoundland, Northwest Territories, Quebec, Yukon), China (5), Mexico (1), United States (99: Georgia, Indiana, Missouri, Nevada, Pennsylvania, South Dakota, Tennessee, Texas, Utah, Virginia, Wyoming, Wyoming-Montana)
Total: 119 collections including 158 occurrences