Parent taxon: Trilobita according to J. M. Adrain 2011
See also Jell and Adrain 2002
Sister taxa: Aglagalia, Agraulaeva, Aguaraya, Aldonaiidae, Altajaharpes, Amechilus, Amgaspididae, Ampellatocephalina, Anacopodia, Antagmidae, Antatlaeva, Atopidae, Auritamidae, Avoninidae, Batchatiella, Bathynotidae, Beikedamaspis, Bergerolimbus, Burlingiidae, Changshaniidae, Chinensis, Corynexochida, Crossoura, Curiaspis, Cuyanaspis, Cyclolenzellina, Dalmanites troosti, Deltacare, Devonocoryphe, Edganocare, Elleria, Elleria morani, Ellipsocephaloididae, Ellipsuella, Entomostracites, Erbenochile, Eulomella, Eutrilobita, Fabulaspis, Faciura, Gentilaspis, Gigmpeltis, Goycoia, Harpetida, Helioproetoides, Howelluella, Idiorapha, Ignotogregatidae, Indigestus, Irvingelloides, Ishpella, Isocolidae, Issafenia, Ityophoridae, Jamrogiidae, Jonotus, Juriietella, Kamlacus, Kanfuqingia, Leptopilus, Libristoma, Lichida, Llanoaspididae, Loxopeltis, Lusampa, Mapaniidae, Megalaspidicus, Meneghinella, Metapopristis, Monkaspididae, Moolatrilo, Moretaeva, Moretarva, Namanoiidae, Neochilonorria, Neomalungia, Neotaenicephalus, Nepeidae, Odontopleurida, Olenida, Onchonotopsidae, Opisthoparia, Orictocara, Otekmaspis, Otenaspella, Paichiashania, Paleoaethia, Parakingaspidoides, Pararania, Peculicephalina, Perissopyge, Phacopida, Phacops (Monorakos), Piliolites, Pliomerellus, Poculicephalina, Polycyrtaspididae, Prodamesella, Proetida, Proparia, Pseudoacicaudus, Pseudoclelandia, Pseudocrecephalaspina, Pseudosalteria, Pseudosarkia, Pseudotermierella, Ptyttstrigis, Punctaspis, Redlichiida, Remopleuridacea, Repinaella, Resseria, Resseropsis, Rochaeva, Sarkiidae, Serksia, Serksioides, Sibiriopeltis, Sphaerocare, Spizharaspis, Stittaspis, Sukhanaspis, Sunaspididae, Taidonurus, Taplimella, Tazemmourtia, Thymurus, Toxotis, Trapezocephalina, Triarthrella, Trilobus, Tuberaspis, Tuyunaspis, Ulrickaspis, Utiidae, Westergardia, Winsteria, Wuaniidae, Zigzuella
Subtaxa: Dasometopus Holocephalina Holocephalites Meneviella Sdzuyella
Type: Holocephalina
Ecology: fast-moving low-level epifaunal carnivore
Distribution:
• Ordovician of Argentina (1 collection)
• Cambrian of China (1), Greenland (2), Kazakhstan (1), the Russian Federation (1), Sweden (2), the United Kingdom (2), United States (2: Alaska, Vermont)
Total: 12 collections including 14 occurrences