Iguanodontidae

Iguanodontids
Temporal range: Early Cretaceous, 126–122 Ma
↓
Iguanodon bernissartensis mounted in modern quadrupedal posture, Royal Belgian Institute of Natural Sciences, Brussels
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: †Ornithischia
Clade: †Neornithischia
Clade: †Ornithopoda
Clade: †Hadrosauriformes
Family: †Iguanodontidae
Bonaparte, 1850
Subgroups

Iguanodontidae is a family of iguanodontians belonging to Styracosterna, a derived clade within Ankylopollexia. The clade is formally defined in the PhyloCode by Daniel Madzia and colleagues in 2021 as "the largest clade containing Iguanodon bernissartensis, but not Hadrosaurus foulkii".[2]

Characterized by their elongated maxillae, they were herbivorous and typically large in size. This family exhibited locomotive dynamism; there exists evidence for both bipedalism and quadrupedalism within iguanodontid species, supporting the idea that individual organisms were capable of both locomoting exclusively with their hind limbs and locomoting quadrupedally.[3] Iguanodontids possess hoof-like second, third, and fourth digits, and in some cases, a specialized thumb spike and an opposable fifth digit.[4] Their skull construction allows for a strong chewing mechanism called a transverse power stroke.[5] This, paired with their bilateral dental occlusion, made them extremely effective as herbivores.[6] Members of Iguanodontidae are thought to have had a diet that consisted of both gymnosperms and angiosperms, the latter of which co-evolved with the iguanodontids in the Cretaceous period.[7]

There is no consensus on the phylogeny of the group. Iguanodontidae is most frequently characterized as paraphyletic with respect to Hadrosauridae,[8][9] although some researchers advocate for a monophyletic view of the family.[10][11]

  1. ^ Lockwood, Jeremy A. F.; Martill, David M.; Maidment, Susannah C. R. (2024-12-31). "Comptonatus chasei, a new iguanodontian dinosaur from the Lower Cretaceous Wessex Formation of the Isle of Wight, southern England". Journal of Systematic Palaeontology. 22 (1). doi:10.1080/14772019.2024.2346573. ISSN 1477-2019.
  2. ^ 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. PMC 8667728. PMID 34966571.
  3. ^ Galton, Peter (1976). "The Dinosaur Vectisaurus valdensis (Ornithischia: Iguanodontidae) from the Lower Cretaceous of England". Journal of Paleontology. 50 (5): 976–984.
  4. ^ Moratalla, J.J. (1992). "A Quadrupedal Ornithopod Trackway from the Lower Cretaceous of La Rioja (Spain): Inferences on Gait and Hand Structure". Journal of Vertebrate Paleontology. 12 (2): 150–157. doi:10.1080/02724634.1992.10011445. JSTOR 4523436.
  5. ^ Godefroit, Pascal (2012). Bernissart Dinosaurs and Early Cretaceous Terrestrial Ecosystems.
  6. ^ Weishampel, David (2012). Evolution of Jaw Mechanisms in Ornithopod Dinosaurs.
  7. ^ Barrett, P.M. (2001). "Did Dinosaurs invent flowers? Dinosaur-angiosperm coevolution revisited" (PDF). Biol. Revs. 76 (3): 411–447. doi:10.1017/s1464793101005735. PMID 11569792. S2CID 46135813.
  8. ^ Cite error: The named reference iguanacolossus was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference AM12 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference old was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference mono was invoked but never defined (see the help page).