WAcanthohoplitesWAmerhippusWAraripichthysWArctotheriumWAtrypaWBaculitesWBarinasuchusWBoreostemmaWCompositaWCuvieroniusWEionaletheriumWFavositesWGlossotheriumWGlyptodonWGlyptotheriumWList of gomphothere fossils in South AmericaWGryposuchusWHippidionWHolmesinaWLaquintasauraWLeptaenaWLestodonWMacraucheniaWMacroscaphitesWMixotoxodonWMourasuchusWMucrospiriferWOnnia (trilobite)WPelagornisWPlatypterygiusWPlatystrophiaWProsqualodonWPurussaurusWRafinesquinaWRequienia (bivalve)WStupendemysWTachiraptorWVinctiferWXenastrapotheriumWXenorhinotheriumWXiphactinus