DINOSA TRS. IOI 
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 
that he was right. Unfortunately, certain popular works on 
geology, such as Our Earth and its Story (Cassell) still continue 
to spread this error, by showing a (very indifferent) restoration of 
Fic. 22.—Skull and skeleton of Zewanodon Mantelli. (From Bernissart.) 
the Iguanodon with the impossible horn on its nose. 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 remains of Iguanodon 
