152 STORY OF THE REPTILES 



land, on account of its weiglit. Another, with ordi- 

 nary feet, had a bill like that of a spoonbill or 

 "shoveler" duck, and fed only on more tender 

 aquatic plants, as is shown by its teeth (Fig. 72). 

 Upon this the terrible Lmla/ps — the talon-toed flesh- 

 eater — is supposed to have fed. 



Fig. 72. — Didonms mirabilis x ^ (after Cope). 



If we glance at Fig. Y3, on page 153, we laay 

 note how birdhke these reptiles were in shape, yet 

 the resemblance was stronger still in structure. It is 

 not necessary, howeverj to believe that birds came 

 from these monsters; but there were some strong 

 bird ward tendencies at work then. On page 154 are 

 the cuts of soriie tracks made by thfese old three-toed 

 bipedal walkers (Fig. 74). 



One of the most peculiar of these giants has been 

 called the fin-backed lizard. It was aquatic, swim- 

 ming by a long flattened tail. The spines on the 

 upper side of the back-bone grew up into a great 

 high arch like a fin; and these, quite likely, had 

 membranes over them or between them. On one of 

 these, found by Professor Cope, there were cross-arms 

 as on the mast of a ship. We can see no use for 



