IGUANODON, ig-wAn'()-(irm (Neo-Lat , from Eng. iguana 4- Gk. inloric, °dolls, tooth). A genus of ornithopod dinosaurs, found fossil in Jurassic and Lower Cretaceous rocks of Europe. Iguanodon is perhaps the first dinosaur brought to light, for it was described by Mantel] in 1825 from specimens found in Bent, England. The animal was 15 to 25 feet long; the head was large and narrow, the jaws heavy and furnished with numerous teeth of peculiar form that resemble those of the modern American lizard iguana. The anterior portions of the jaws are provided \vitt] strong, horny beaks like those of turtles. The fore limbs have four toes and a 'spur,' and are much shorter than the heavy three-toed hind limbs. The pelvis is elongated, and the tail heavy, and there is a ridge of strong vertebral spines extending along the dorsal surface from the neck to the middle of the tail: All the bones are hollow. Iguanodon was an herbivorous dino saur that walked on its hind legs, and sat on a tripod formed by the hind legs and tail. after the
manner of the kangaroo. It lived in great num bers in the swampy regions of England and Bel gium. and other parts of Europe during Jurassic time, as indicated by the mode of occurrence of its fossil skeletons, twenty-nine of which were found at one time in Upper .Iurassie sandstones of the coal regions at Bernissart, Belgium.
Iguanodon has not been found in the Mesozoies of America, where it is represented by similar genera • 'amptosatirns, Laosau•ns. and •hesp• sins. A very instructive account of the disco‘ery and 111 rly history of Iguanodon, illustrating the method by which fragmentary material has after careful work yielded valuable results, is to be found in Mantell's trifaetions and Their Iqs I London, 1551). See also Woodward. notiims of Vcrtchrate Pahrotttoloyy for Students of Zooloyy (I'amb•idge. 1595). See C.v.m PTO SA DINOSAURIA.