WAistopoda
WAthyridida
WBourgueticrinida
WCaptorhinida
WChoristodera
WChroniosuchia
WCladida
WCornulitida
WCornuta
WCystoporida
WEosuchia
WGogiida
WMicroconchida
WMillericrinida
WMillerosauria
WMorganucodonta
WMultituberculata
WOrthida
WPentamerida
WProcolophonomorpha
WProductida
WPtolemaiida
WStrophomenida
WTabulata
WTemnospondyli
WThecodontia
WTrepostomata