Parent taxon: Arthropoda according to D. J. Siveter et al. 2004
Sister taxa: Actaeus, Almenia, Arachnida, Arachnoidea, Aristocaris, Bostrichopus, Bradoriida, Bundenbachiellus, Burgessia, Cambropachycope, Cindarella, Clypecaris, Conchostraca, Conciliterga, Corcorania, Crustacea, Dalmaniopsis, Dicerocaris, Dongshanocaris, Douglasocaris, Duslia, Emeiella, Ercaia, Forfexicaris, Fuxianhuiida, Gaoqiaioella, Gigantopleurida, Goticaris, Guangweicarididae, Habelia, Hanburia, Helmetia, Henningsmoenicaris, Hexapoda, Huangshandongia, Isoxys, Jianfengia, Jiucunella, Kablikia, Kleptothule, Kuamaia, Liantuoia, Longquania, Mandibulata, Marrella, Marrelomorpha, Martinssonia, Meristosomo, Merostomoidea, Molaria, Mollisonia, Motina, Myriapoda, Naptile, Nektaspida, Occacaris, Odaraia, Orstenocarida, Orstenotubulus, Oxyuropoda, Pahvantia, Panlongia, Parapaleomerus, Paratrilobita, Parvancorinomorpha, Pauloterminus, Pectocaris, Pisinnocaris, Platicytes, Plenocaris, Priscansermarinus, Protocarcinus, Protocaris, Pseudarthron, Pseudoarctolepis, Pseudoiulia, Pygmaclypeatus, Quasicaris, Rehbachiella, Retifacies, Rhombicalvaria, Saperion, Schizodiscus, Scorpionida, Serracaris, Shafferia, Shankouia, Sinoburius, Skaracarida, Skioldia, Squamacula, Tanglangia, Thylacocephala, Urokodia, Utahcaris, Walossekia, Xandarella, Dinocarida, Arachnomorpha, Trilobita, Schinderhannes, Proschizoramia
Subtaxa: Gumatagichnus, Merostomata, Offacolidae, Pycnogonida
Ecology: