Parent taxon: Aequornithes according to G. Sangster and G. Mayr 2021
See also Carroll 1988, del Hoyo et al. 2014, Guthrie 1992, Hay 1930, Hope 2002, Howard 1972, Livezey and Zusi 2007, Mayr 2005, Mayr 2022, Parmalee 1992, Slack et al. 2006, Wetmore 1940 and Wetmore 1956
Sister taxa: Feraequornithes, Lonchodytes
Subtaxa: Gaviidae Lonchodytidae Petralca
Distribution:
• Quaternary of Canada (9: Northwest Territories, Nunavut, Quebec, Yukon collections), Finland (12), Japan (2), the Russian Federation (2), Spain (1), Taiwan (1), Ukraine (1), United States (41: Alabama, Alaska, California, Florida, Maryland, Virginia)
• Blancan of United States (6: California)
• Pliocene of United States (6: California, North Carolina)
• Miocene of Austria (2), France (1), Ukraine (1), United States (8: California, Delaware, Florida, Maryland, North Carolina, Virginia)
• Oligocene of Belgium (1), Germany (2), Kazakhstan (1), United States (1: Wyoming)
• Eocene of Canada (1: British Columbia), Ukraine (1)
• Cretaceous of United States (1: Wyoming)
Total: 101 collections including 131 occurrences