Alternative spelling: Harpida
Parent taxon: Ptychopariida according to R. A. Fortey 1990
See also Adrain 2011, Beech and Lamsdell 2021, Ebach and McNamara 2002, Harrington et al. 1959, McNamara et al. 2009 and Sepkoski 1998
Sister taxa: Acrocephalitidae, Alokistocaridae, Amphorella, Atratebiinae, Bifodina, Bolaspididae, Bulnibarbi, Bvalbardites, Catillicephalidae, Chondrastaulina, Chuangiformis, Cliffiidae, Conococheaquea, Conocoryphidae, Conokephalinidae, Crepicephalidae, Diceratocephalidae, Elviniidae, 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: none
Ecology: fast-moving low-level epifaunal carnivore
Distribution: