9 
I)i> losaurla — S auropoda . 
biconcave centra to tlieir vertebrae, the anterior (cervical) 
vertebrae had hollow cups behind. Two pairs of limbs were 
always present, furnished with strong-clawed digits. 
They were probably to some extent amphibious in their 
habits, but their limbs were well fitted for progression on the 
land. 
The group has been provisionally sub-divided into the 
following- sub-orders, namely : — 
Dinosauria 
Sub-order 1. — Sauropoda (Lizard-footed). 
The members of this group of Dinosaurs were all herbi- Atlantosau 
vorous, and included some of the largest forms hitherto dis- -^all-case, 
covered, by far the hugest being the American genus Atlan- No. 3. 
tosaurus , from the Jurassic of Colorado. Although no entire 
skeleton has been found, it is supposed to have attained a 
Fig. 12.— Lateral view of skull of Diplodocus longus (Marsh), from the “ Atlantosaurus" beds 
(Upper Jurassic), near Canon City, Colorado, N. America (| nat. size). 
(Not yet represented in the Collection.) 
length of over 80 ft., and a height of 30 ft., as from the struc- 
ture and relative proportions of the fore and hind limbs, it is 
assumed that these huge reptiles walked in an erect, or a 
semi-erect position, on their hind-feet. A plaster-cast of a 
thigh-bone (femur) shown in this case is 6 ft. 3 in. long. 
Another remarkable genus, from the same horizon and 
locality, is the Diplodocus, an animal intermediate in size between 
Atlantosaurus and Morosaurus , which may perhaps have attained 
to 40 or 50 feet in length, when living. The teeth indicate that 
it was herbivorous and its food was probably succulent vegeta- 
