ORDER VIH 



DINOSAURIA 



239 



ramus composed of six pieces, and with slender coronoid process. There are 

 teil cervical, eighteen dorso-lumbar, four to six sacral, and forty to fifty caudal 

 vertebrae. All the presacral vertebrae except the atlas and a few lumbars 



bear ribs, as do also the thirteen 



anterior caudals. Ossified tendons 



frequently observed along the neural 



' ** ^K5^ spines of the back and tail. Scapula 



very long and slender ; coracoid 

 small and rounded, notched or per- 

 forate at its articular border ; 

 supposed pair of sternal bones 



>.^-'' 



Fig. 341 



Ljuanodoii mantelli, Owen. Wealden ; Isle of Wight. 

 Inner (A), and posterior (B) aspects of mandibular tooth 

 (after Mantell). 



triangulär. Manus 

 pentadactyl, the 

 pollex reduced to a 

 Single spur-like 

 phalanx ; the others 

 having a formula of 

 3, 3, 3, 4. Iliuni 

 greatly extended on 

 either side of the 

 acetabulum. Post- 

 pubis process slender 

 and rod-like, shorter 

 than the ischium. 



Fio. 34S 



Jguunodon bernissartensis, Boul. Wealden ; Bernissart, Belgiiun. Complete 

 skeleton, i/ßo- co, Coracoid ; is, Ischium ; p, Pubis ; pj>, Postpubic process ; sc, 

 remur SCarcely Scapula ; I— V, Digits (after Dollo). 



ionger than the crus, 



and with prominent pendent inner trochanter. This, according to Dollo, is 

 distinct from the third trochanter of mammals, and indicates a powerful caudo- 

 femoral musculature, as in birds. Metatarsal No. l rudimentary, No. V wanting ; 

 the three ungual phalanges broad and claw-shaped ; formula of pes, 0, 3, 4, 5, 0. 

 Iguanodon is known by numerous complete skeletons from the Wealden of 

 Bernissart, near Mons, Belgium, as many as twenty -three being exhibited in the 

 Brüssels Museum. Fragmentary remains occur also in the English Wealden. 

 Lower Greensand, Purbeckian, and perhaps also in the Kimmeridge Clay. The 

 typical species, /. mantelli, Owen, from the Wealden of England, attains a total 

 length of 6 m., and /. bernissartensis, Boulenger ( = /. seelej/i, Hulke), is between 

 8 and 10 m. long. As proved by its three-toed footmarks, the animal walked 

 on its bind feet in a kangaroo-like attitude, thus leaving the hands free for 

 prehension. 



