WAmebelodontidae
WAnancidae
WBarbourofelidae
WBramatherium
WChalicotheriinae
WChoerolophodontidae
WChunga (bird)
WClimacoceratidae
WCosmopolitodus
WDesmatophocidae
WDryopithecini
WEocardia
WEocardiidae
WGlyptodont
WHomotherini
WHorned gopher
WHydrodamalinae
WMachairodontinae
WMammutidae
WMegalodon
WMeiolania
WMoa
WMylodontidae
WOtavipithecus
WOtavipithecus
WPelocetidae
WPercrocutidae
WPlatygonus
WPliopithecoidea
WPraekogia
WProconsulidae
WSchizotheriinae
WThylacosmilidae