THE DRAGONS OF OLD TIME— DINOSAURS. 71 
Morosaiirus, another important genus, is known from a large 
number of individuals discovered in the now famous Atlantosaurus 
beds of Colorado, including one nearly complete skeleton. The 
head of this creature was small ; the neck elongated * and the 
vertebrae of the neck are lightened by deep cavities in their centra, 
similar to those in birds of flight. The tail, also, was long. When 
alive, this Dinosaur was about forty feet in length. It probably 
walked on all fours ; and in many other respects was very unlike 
a typical Dinosaur. The brain was small, and it must have been 
sluggish in all its movements. The nearly complete remains of 
Morosaurus grandis were found together in a very good state of 
preservation in Wyoming, and many of the bones lay just in 
their natural positions. 
Diplodocus, of which several incomplete specimens have been 
discovered, was intermediate in size between Atlantosaurus and 
Morosaurus, and may have reached when living, a length of forty 
or fifty feet. Its skull was of moderate size, with slender jaws^ 
The teeth were weaker than those of any other known Dinosaur, 
and entirely confined to the front of the jaws. Professor Marsh 
concludes from the teeth that Diplodocus was herbivorous, feeding 
on succulent vegetation, and that it probably led an aquatic life. 
Fig. II shows its skull. 
The remains of this interesting Dinosaur (Brontosaurus), which 
in several ways differs from other members of the “ lizard-footed ” 
group, were found in Upper Jurassic beds, near Canon City, Colo- 
rado. A second smaller species was also discovered near Morrison, 
Colorado. All the remains lay in the Atlantosaurus beds. These 
strata — the tomb in which Nature has buried up so many of her 
dragons of old time — can be traced for several hundred miles on 
the flanks of the Rocky Mountains, and are always to be known 
by the bones they contain. They lie above the Triassic strata 
and just below the Sandstone of the Dakota group. Some have 
regarded them as of Cretaceous age ; but, judging from their 
fossils, there can be but little doubt that they were deposited 
