2 FOSSIL REPTILIA OF THE 



Description of part of the Skeleton of a Young Iguanodon. Tab. I. 

 Iguanodon Mantelli, Mantell. 



A considerable and very instructive part of the skeleton of a young Iguanodon, 

 the entire body of which was probably under two yards in length, was discovered in 

 the Wealden formations, about one hundred yards west of Cowleaze Chine, on the 

 south-west coast of the Isle of Wight, in the year 1849. 



The mass of Wealden stone in which this skeleton was imbedded, was broken into 

 two parts in its extraction from the bed ; and, as happened with the skeleton of the 

 Dolichosaurus, described in a former Monograph,* the workmen disposed of one part 

 to one collector, and of the other to another. Mr. Bowerbank was so fortunate as to 

 become the possessor of that portion which contained the most important part of the 

 skeleton, and which forms the upper division of the chief figure in the plate, Tab. I, 

 where it is represented of the natural size. 



This portion includes seventeen vertebrae, extending from the neck to near the 

 pelvis inclusive : the pelvis apparently forms a continuation of the vertebral series, but 

 is obscured by the principal bones of the right hind foot, mt, pi, l and 2. Some portions 

 of ribs, pi, pi, and of a coracoid, 52, in the proximal part of the left femur, 65, the distal 

 halves of the right tibia, 66, and fibula, 67, and a fragment of the left tibia, 66, are also 

 imbedded in the same block of stone. The other portion of the block fell into the 

 possession of Dr. Mantell, and is now in the British Museum. It includes eleven con- 

 secutive caudal vertebrae, with some of their haemapophyses, h, h ,• the right femur, 65, the 

 proximal halves of the right tibia, 66, and fibula, 67, and parts of the left tibia, 66', 

 and fibula, 67'. The bones of the right hind leg are almost completed when the blocks 

 containing their opposite ends are brought into juxtaposition, as in Tab. I. 



Of the seventeen vertebrae, in Mr. Bowerbank's specimen, the three anterior, 

 l, 2, 3, have been detached and carefully worked out: they appear to have immediately 

 preceded the rest which remain imbedded in the block, and which are unequivocally 

 consecutive ; including the detached three, the seventeen vertebrae occupy an extent of 

 thirteen inches. 



The first three vertebrae, as imbedded and naturally cemented together, exhibit a 

 slight upward curvature, and the five following vertebrae are bent in the same direction, 

 but in a less degree : the rest present a moderate bend with the concavity down- 

 wards or towards the abdomen. The whole of this series, therefore, describes a gentle 

 sigmoid curvature, like that which may be observed in the naturally articulated 



* ' Fossil Reptilia of the Cretaceous Formations,' 1851, 4to, p. 22. Cuvier had to contend with similar 

 difficulties; see 'Ossem. Foss.,' t. v, pt. ii, p. 148. 



