Full reference: E. L. Yochelson. 1977. Agmata, a proposed extinct phylum of Early Cambrian age. Journal of Paleontology 51:437-454
Parent taxon: Metazoa according to E. L. Yochelson 1977
Sister taxa: Bilateria, Diploblastica, Homoblastica, Hyolithelminthida, Vertebrosa, Westgardia, Tetraradialomorpha, Broccoliforma, Parazoa, Dictyorhabdus, Chondroplon, Arboreomorpha, Epitheliozoa, Yunnanomedusa, Odontogriphidae, Mesozoa, Silicea, Xidazoon, Gaojiashania, Erniettomorpha, Ventogyrus, Evmiaksia, Megathrix, Tentaculitoidea, Gephyrea, Sentularia, Helanoichnus, Bomakellia, Subtilicyathus, Protolyellia, Nectocarididae, Khasaktidae, Kinzeriidae, Problematica, Kimberellomorpha, Euradiculata, Somatohelix, Yangtziramulus, Bilaterialomorpha, Pentaradialomorpha, Muricassis, Eodiorygma, Cnidaria, Rhizostomites, Goettingenia, Porifera, Bronicella, Oligoopilionus, Palaeacmaea, Petalonamae, Triradialomorpha, Hadrynichorde, Spygoria, Proarticulata, Hadryniscala, Eumetazoa, Atalotaenia, Scenellopsis, Convolutubus, Lazaichnus, Siphonoconcha, Limacites, Macrocypris kayi, Silicispongea, Trichoplax, Persimedusites, Lidaconus, Chenmengella, Yelovichnus, Deuteronectanebos, Lomosovis, Kuckaraukia
Subtaxa: Salterellidae Volborthellida Volborthellidae
Distribution:
• Ordovician of United States (1: Tennessee collection)
• Cambrian of Argentina (1), Canada (10: Labrador, Neufundland and Labrador, Newfoundland and Labrador, Quebec, Yukon Territory), the Czech Republic (3), Denmark (1), Greenland (9), Mexico (2), Norway (6), Sweden (3), the United Kingdom (8), United States (23: California, Nevada, Pennsylvania, Virginia)
• Caerfai of Canada (1: Northwest Territories)
• Waucoban of United States (1: California)
Total: 69 collections including 72 occurrences