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 and Kröger and Landing 2009
Sister taxa: Acaroceratidae, Antacaroceras, Balkoceratidae, Bambusoceras, Bathmoceratidae, Cyptendocerina, Cyrtocerinina, Ellesmeroceratidae, Ellesmeroceratina, Eocyckistomiceras, Eothinoceratidae, Huaiheceratidae, Hunyuenoceras, Parapalaeoceras, Phthanoncoceratidae, Plectronoceratidae, Plectronoceratina, Qiushougouceras, Rioceratidae, Rudolfoceratidae, Shideleroceratidae, Theskeloceras, Vassaroceras, Xiaoshaoceras
Subtaxa: Bakeroceras Catoraphiceras Catoraphinoceras Cyptendoceras Diastoloceras Endocycloceras Kyminoceras Notocycloceras Protocycloceras
Ecology: nektobenthic carnivore
Distribution:
• Carboniferous of United States (7: Ohio, Pennsylvania collections)
• Whiterockian of United States (2: Utah)
• Arenig of Argentina (1), Bolivia (1), China (16), Sweden (1)
• Dawan of China (8)
• Ordovician of Argentina (1), Bolivia (1), Canada (12: Newfoundland, Newfoundland and Labrador, Ontario, Quebec), China (10), the Russian Federation (1), Svalbard and Jan Mayen (2), Sweden (1), the United Kingdom (22), United States (34: Alabama, Arkansas, Colorado, Maryland, Minnesota, Missouri, Nevada, New Mexico, New York, Tennessee, Texas, Utah, Vermont)
• Tremadoc of Argentina (1), China (2), the Russian Federation (1)
Total: 124 collections including 142 occurrences