iguanodontidæ

Century Dictionary and Cyclopedia

1. A family of gigantic extinct dinosaurs, typified by the genus Iguanodon, belonging to the order Dinosauria (or Ornithoscelida), possessing clavicles and an incomplete post-pubis. These enormous saurians present a bird-like type of structure, especially in the hind limbs. The pelvic bones are strikingly like those of birds, especially in the length and slenderness of the ischium and pubis, and the obturator process of the former bone. The hind limbs are enlarged in comparison with the fore limbs; the anterior vertebræ are slightly amphicælous, the posterior flat; the premaxillæ are beak-like and toothless; and the mandibular symphysis is notched to receive the beak, as in some birds. The teeth are large and broad, transversely ridged, implanted in sockets and not ankylosed to the jaw, and worn down by mutual attrition. There does not appear to have been any dermal armor. Several genera besides Iguanodon have been referred to this family, as Hypsilophodon, Scelidosaurus, and others; its limits vary with different writers.