HATCHER: OSTEOLOGY OF HAPLOCANTHOSAURUS 61 
ripple marks and even occasionally exhibiting footprints is conclusive proof that 
such sandstones had not their origin in the midst of a great lake, while the presence 
almost everywhere of the remains of terrestrial reptiles and less frequently of 
mammals tells only too plainly of an adjacent land-mass. In all this region I know 
of no locality where any considerable extent of the Atlantosaurus beds occurs, in 
which remains of quadrupedal, terrestrial dinosaurs have not been found. To my 
mind, this fact alone affords very strong presumptive evidence that in Jurassic times 
Fa 
Fic. 23. Photograph of footprint in Jurassic SINTON, near Canyon City, Colorado. 
this entire region was the habitat of these dinosaurs, which it could not have been 
had it been covered by a great lake, for the structure of their limbs shows con- 
clusively that the Dinosauria were not aquatic. Nor can I conceive of the possi- 
bility of the carcasses of terrestrial animals being carried out into the midst of so 
great a lake as that presupposed above and left in such abundance as the numbers 
of their bones in these deposits would indicate. An hypothesis, which it appears to 
me is far more reasonable and more nearly in accordance with the facts as we now 
know them, is to consider this region as presenting in late Jurassic and early Creta- 
