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, Kosovoceras, Magdoceras, Ophidioceratidae, Pakrioceras, Pseudancistroceras, Tarphyceratidae, Trocholitidae, Weberoceratidae
Subtaxa: Aethoceras Alaskoceras Aphetoceras Clytoceras Deltoceras Eichwaldoceras Estonioceras Pycnoceras Shumardoceras Tragoceras
Ecology: fast-moving nektobenthic carnivore
Distribution:
• Ordovician of Canada (3: Newfoundland, Newfoundland and Labrador, Quebec collections), China (1), Norway (1), Sweden (1), the United Kingdom (3), United States (27: Arkansas, Missouri, New York, Tennessee, Texas)
• Chazy of United States (2: New York)
• Arenig of China (1)
• Cassinian of United States (1: Missouri)
• Canadian of Australia (1)
• Jefferson of United States (2: Missouri, Oklahoma)
• Jeffersonian of Canada (1: Newfoundland and Labrador), United States (2: Missouri)
Total: 46 collections including 59 occurrences