Hadrosauriformes
Hadrosauriformes is a clade of styracosternan ornithopods defined as the most recent common ancestor of Iguanodon and Hadrosaurus and all its descendants, uniting iguanodontid-grade forms with the hadrosauroids and the duck-billed Hadrosauridae. Across the clade, dental batteries grew increasingly complex, and the snout trended from the narrower beak of early iguanodontian-grade members toward the broad, edentulous bill of the most derived hadrosaurids. Its members were large-bodied herbivores known from Europe, Asia, Africa, and the Americas, making Hadrosauriformes one of the most geographically widespread and successful ornithischian radiations of the Cretaceous.
Diagnosis
- Dental battery with multiple stacked replacement teeth per tooth position
- Broad, flattened, edentulous premaxillary bill
- Reduction or loss of the manual pollex spike in derived members
- Elongate, dorsoventrally low rostrum
Clades within Hadrosauriformes
- Hadrosauroidea 117 genera
Genera placed directly in Hadrosauriformes
- Comptonatus Barremian (125.8–121.4 Ma)United Kingdom
- Iguanodon Barremian–Aptian (125.8–113.2 Ma)Belgium
- Mantellisaurus Barremian–Aptian (125.8–113.2 Ma)United Kingdomunder dispute
- Siamodon Disputed Aptian (121.4–113.2 Ma)Thailand
References
-
Sereno, P. C. (1997). The origin and evolution of dinosaurs. Annual Review of Earth and Planetary Sciences 25: 435-489.
Listed Hadrosauriformes in its unranked classification of Dinosauria, without a definition; Madzia and colleagues (2021) credit the name to this paper.
sereno1997a -
Madzia, D.; Arbour, V. M.; Boyd, C. A.; Farke, A. A.; Cruzado-Caballero, P.; Evans, D. C. (2021). The phylogenetic nomenclature of ornithischian dinosaurs. PeerJ 9: e12362. doi:10.7717/peerj.12362
Provides the modern phylogenetic definition of Hadrosauriformes.
madzia2021a