Iguanodontidae
[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.Iguanodontidae is most frequently characterized as paraphyletic with respect to Hadrosauridae,[8][9] although some researchers advocate for a monophyletic view of the family.In some cases, it is possible that digits three and four were bound into a single structure by layers of skin, a specialized adaptation for quadruped locomotion.[13] That is, iguanodontids represent successive steps in the acquisition of advanced hadrosaurian characteristics, and in this view cannot be defined as a single distinct clade.[8] The left cladogram was recovered in a 2015 analysis that supports a monophyletic Iguanodontidae,[11] whereas the right cladogram from 2012 study finds the group to be paraphyletic:[9] Camptosaurus Batyrosaurus Ouranosaurus Hadrosauroidea Barilium Iguanodon Mantellisaurus Proa Bolong Jinzhousaurus Camptosaurus Uteodon Hippodraco Theiophytalia Iguanacolossus Lanzhousaurus Kukufeldia Barilium Iguanodon Mantellisaurus Hadrosauroidea Fossilized footprints provide evidence for both quadrupedality and bipedality within iguanodontids.These dinosaurs were very effective as herbivores due in part to their combination of bilateral dental occlusion with the transverse power stroke of their chewing mechanism.Additionally, iguanodontids lack a rigid secondary palate, which helps to mitigate torsional stresses during occlusion, a feature that enhanced their ability to break down plant matter.Angiosperms typically develop more rapidly and lower to the ground than gymnosperms; their proliferation provided a wealth of easily accessible food for the members of Iguanodontidae.
Early CretaceousPreꞒIguanodonRoyal Belgian Institute of Natural SciencesScientific classificationEukaryotaAnimaliaChordataDinosauriaOrnithischiaOrnithopodaHadrosauriformesBariliumBolongComptonatusJinzhousaurusLurdusaurusMantellisaurusiguanodontiansStyracosternaAnkylopollexiaPhyloCodeIguanodon bernissartensisHadrosaurus foulkiibipedalismquadrupedalismpower strokegymnospermsangiospermsCretaceousphylogenyparaphyleticHadrosauridaemonophyleticantorbital fenestralacrimalenamellanceolatepremaxillaryadaptationhoovescervical vertebraeneural archesossifiedischiumhumerusradiusHypsilophodontidaeCamptosaurusBatyrosaurusOuranosaurusHadrosauroideaUteodonHippodracoTheiophytaliaIguanacolossusLanzhousaurusKukufeldiaherbivoreshorsetailsocclusionsecondary palateJournal of Systematic PalaeontologyBibcodeNeornithischiaCerapodaAvemetatarsaliaBurianosaurusCallovosaurusThescelosauridaeGideonmantelliaHypsilophodonVectidromeusElasmariaAnabisetiaAtlascopcosaurusChakisaurusDiluvicursorFostoriaGalleonosaurusGasparinisauraIsasicursorKangnasaurusLeaellynasauraMacrogryphosaurusMahuidacursorMorrosaurusMuttaburrasaurusNotohypsilophodonQantassaurusSektensaurusTalenkauenTietasauraTrinisauraWeewarrasaurusRhabdodontomorphaAmpelognathusEmiliasauraTenontosauridaeConvolosaurusTenontosaurusRhabdodontidaeMatheronodonMochlodonPareisactusRhabdodonTransylvanosaurusZalmoxesDryomorphaDraconyxHesperonyxOwenodonDryosauridaeDryosaurusDysalotosaurusElrhazosaurusEousdryosaurusValdosaurusBayannurosaurusCalvariusCedrorestesCumnoriaDakotadonFukuisaurusMagnamanusNapaisaurus