Hadrosauroidea is a clade or superfamily of ornithischian dinosaurs that includes the "duck-billed" dinosaurs, or hadrosaurids, nd their close relatives. Many primitive hadrosauroids, such as the sail-backed Ouranosaurus, have traditionally been included in a paraphyletic (unnatural grouping) "Iguanodontide". With cladistic analysis, the traditonal Iguanodontidae has been largely disbanded, and probably includes only Iguanodon and perhaps its closest relatives.
- Superfamily Hadrosauroidea
Cladogram after Norman (2002) and Godefroit, Li & Shang (2005).
Hadrosauroidea |--Penelopognathus |--+--Altirhinus | `--Eolambia `--+--Protohadros `--+--Probactrosaurus `--Hadrosauridae |--Telmatosaurus `--+--Bactrosaurus `--Euhadrosauria |--Hadrosaurinae `--Lambeosaurinae