492 



GEOLOGY OF THE DENVER BASIN. 



This species had a short, massive neck, and hence was called Apatosaurus 

 laticollis. The size of the entire animal may be judged from this vertebra, 

 which measures over 3} feet (1.07 meters) in width. This would imply a 

 neck not less than 5 or 6 feet wide at this point. 



BROM rOSAI RUS. 



In the Atlantosaurus beds of the Wyoming Basin the genus Bronto- 

 saurus is well represented by two or more gigantic species, one of which 



Fig. 39.— Tooth of lirontnmurus excelsus Marsh. Natural size, 

 a, outer view; b, posterior view ; c, inner view; if, front view. 



Fir.. 40.— Sixth cervical vertebra of Brontosaurus excelsus ; front view. 

 Fig. 41.— The same vertebra; bottom view. 

 Both fignree are one .twelfth natural size. 



h. hall; d, diapophysis; / lateral foramen; «. neural .anal;;., parapophy sis ; 

 pophvsis; ~\ posterior zygapophysis. 



z, anterior zyga- 



is shown in the restoration on PI. XXI. Various remains apparently 

 identical with this species have been found in the Denver region, and 



