DINOSAURS 



165 



feet in length. It will be seen that the fore limbs are small in 

 comparison to the hind limbs. A remarkable feature of the hand 

 is the large pointed bone at the end of the thumb, forming a kind 

 of spur. The conical shape of this bone found by Dr. Mantell, 

 who had no clue to its place in the skeleton, led him to suppose 

 that it was a horn answering to that of a rhinoceros a conclusion 

 which Professor Owen refused for various reasons to accept. The 

 latter concluded that it belonged to the hand, and now we see 



FIG. 55. Skull and skeleton of Iguanodon Mantelli. (After Dollo.) 



that he was right. It has been suggested that the spur was a 

 weapon of offence, and that, when attacked, an Iguanodon may 

 have seized its aggressor in its short arms, and made use of the spur 

 as a dagger. But this is only conjecture, and perhaps the spur may 

 have been useful in seizing and pulling down the foliage and 

 branches of trees, or in grubbing them up by the roots. Detached 

 specimens of this curious bone may be seen among the other 



