WBrule Formation
WOtodus angustidens
WColumbia River Basalt Group
WConiophis
WCynthiacetus
WEpihippus
WEuclastes
WFerris Formation
WLaramide orogeny
WLeptomeryx
WMarysvale volcanic field
WOrohippus
WOtodus auriculatus
WWhite River Formation
WWilcox Group
WXiphiorhynchus