OUTGROUPIguanodonOuranosaurusProbactrosaurusTelmatosaurusGilmoreosaurusGryposaurusMaiasauraBrachylophosaurusEdmontosaurusAnatotitanProsaurolophusSaurolophusBactrosaurusEolambiaParasaurolophusLambeosaurusCorythosaurusHypacrosaurusOsteologyMaximum ParsimonyBased on reanalysis of the original matrix.Kirkland_1998a