[1] Eryosuchus was named by Ochev (1966) based on the type species, E. tverdochlebovi from exposures of the Donguz Formation in Orenburgskaya Oblast.

Schoch & Milner's concept, that of an exclusively Russian clade and that is adopted by most other workers, listed only two synapomorphies of the genus: intermediately sized orbits (larger than most capitosauroids other than mastodonsaurids) and an elongate post-glenoid area (PGA) that is shallowly concave and with a medial ridge aligned sagittally.

Damiani's (2001) more expansive concept listed only laterally directed tabular horns with an antero-distal 'lappet' as apomorphic for this genus.

[9] Below is the phylogeny from Fortuny et al. (2011); E. garjainovi is typically used as the representative of this genus:[10] Lydekkerina huxleyi Rhineceps nyasaensis Uranocentrodon senekalensis Wetlugasaurus angustifrons Odenwaldia heidelbergensis Vladlenosaurus alexeyevi Edingerella madagascariensis Watsonisuchus spp.

Quasicyclotosaurus campi Parotosuchus orenburgensis Calmasuchus acri Cyclotosaurus robustus Tatrasuchus wildi Eryosuchus garjainovi Mastodonsaurus giganteus Benthosuchus sushkini Thoosuchus yakovlevi Angusaurus spp.