Cephalopoda - Ellesmerocerida - Protocycloceratidae
Synonym: Rhabdocycloceratidae Zhuravleva 1994
Parent taxon: Ellesmerocerida according to B. Kröger and D. H. Evans 2011
See also Crick 1981, Evans 2011, Flower 1964, Hook and Flower 1977, Kröger and Landing 2009 and Zhuravleva 1994
Sister taxa: Acaroceratidae, Antacaroceras, Balkoceratidae, Bambusoceras, Bathmoceratidae, Cyptendocerina, Cyrtocerinina, Ellesmeroceratidae, Ellesmeroceratina, Eocyckistomiceras, Eothinoceratidae, Huaiheceratidae, Hunyuenoceras, Parapalaeoceras, Phthanoncoceratidae, Plectronoceratidae, Plectronoceratina, Qiushougouceras, Rudolfoceratidae, Shideleroceratidae, Theskeloceras, Vassaroceras, Xiaoshaoceras
Subtaxa: Bakeroceras Catoraphiceras Catoraphinoceras Cyptendoceras Diastoloceras Endocycloceras Kyminoceras Notocycloceras Paracatoraphiceras Protocycloceras
Ecology: nektobenthic carnivore
Distribution:
• Whiterockian of United States (2: Utah collections)
• Billingen of Sweden (1)
• Arenig of Argentina (1), Bolivia (1), China (16), Sweden (1)
• Dawan of China (8)
• Ordovician of Argentina (2), Bolivia (1), Canada (12: Newfoundland, Newfoundland and Labrador, Ontario, Quebec), China (12), the Russian Federation (2), Svalbard and Jan Mayen (2), the United Kingdom (22), United States (34: Alabama, Arkansas, Colorado, Maryland, Minnesota, Missouri, Nevada, New Mexico, New York, Tennessee, Texas, Utah, Vermont)
Total: 117 collections including 135 occurrences