Synonym: Champsosauriformes Hay 1930 [replaced name]
Parent taxon: Choristodera according to R. Matsumoto et al. 2019
See also Dong et al. 2020, Gao and Fox 2005, Gao and Li 2007, Hay 1930, Matsumoto et al. 2013, Matsumoto et al. 2007 and Yuan et al. 2021
Sister taxa: Allochoristodera, Coeruleodraco, Cteniogenyidae, Heishanosaurus, Hyphalosauridae, Hyphalosaurus, Irenosaurus, Khurendukhosaurus, Lazarussuchus, Monjurosuchidae, Monjurosuchus, Novapes, Pachystropheus, Philydrosaurus, Shokawa
Subtaxa: Champsosauridae Champsosaurus Ikechosaurus Mengshanosaurus Simoedosauridae Tchoiria
Ecology:
Distribution:
• Eocene of Belgium (2 collections), Kazakhstan (1)
• Paleocene of Canada (7: Alberta, Saskatchewan), France (2), Kazakhstan (1), United States (36: Colorado, Montana, North Dakota, Texas, Utah, Wyoming)
• Cretaceous of Austria (1), Canada (102: Alberta, Nunavut, Saskatchewan), China (10), Japan (1), Mongolia (5), the Russian Federation (3), United States (106: Colorado, Montana, New Jersey, North Dakota, South Dakota, Utah, Wyoming)
Total: 277 collections including 288 occurrences