Cephalopoda - Tarphycerida - Estonioceratidae
Synonym: Deltoceratidae Ulrich et al. 1942
Parent taxon: Tarphycerida according to D.H. Evans 2011
See also Crick 1981, Kröger and Landing 2008, Kröger and Mutvei 2005 and Stait 1983
Sister taxa: Bateroboceras, Bodieceras, Craftonoceras, Discoceratidae, Inclytoceras, Magdoceras, Ophidioceratidae, Pakrioceras, Pseudancistroceras, Tarphyceratidae, Trocholitidae, Weberoceratidae
Subtaxa: Aethoceras Alaskoceras Aphetoceras Clytoceras Deltoceras Eichwaldoceras Estonioceras Pycnoceras Shumardoceras Tragoceras
Ecology: fast-moving nektobenthic carnivore
Distribution:
• Chazyan of United States (2: New York collections)
• Hunderum of Sweden (1)
• Arenig of China (1)
• Canadian of Australia (1)
• Ordovician of Canada (4: Newfoundland, Newfoundland and Labrador, Quebec), China (1), Norway (1), the United Kingdom (3), United States (32: Arkansas, Missouri, New York, Oklahoma, Tennessee, Texas)
Total: 46 collections including 59 occurrences