(Youngina,(Squamata,(Gephyrosaurus,(Diphydontosaurus,(Planocephalosaurus,(Palaeopleurosaurus,(((Polysphenodon,Brachyrhinodon),((Clevosaurus_hudsoni,Clevosaurus_petilus),(Clevosaurus_bairdi,Clevosaurus_mcgilli))),(Homoeosaurus,(Kallimodon,(Sapheosaurus,(Pamizinsaurus,((Zapatadon,(Eilenodon,Toxolophosaurus,Opisthias)),(Cynosphenodon,Sphenodon)))))))))))));