JURASSIC VERTEBRATE FOSSILS. 



507 



The turtles appear to have been more abundant, and still more distinct 

 from living tonus. The most characteristic genus is Glyptops, and a skull 

 and carapace of one species are represented in figs. 63 and 64, below. The 



Fib. 62.— Skullol Diplosaurut/elixMaxah top view >-fourtl: natui 



u aasal aperture; o, orbit; oc, occipital condyle s, supratexnporal fossa. 

 Fiu. 63.— Skull of Glyptopt ornatui Marsh; top view. Natural Bize. 



I !■ t*.4— Carapace ot same sprcies lop view. One- fourth natural Size. 



generic name refers to the sculptured surface of the skull, which is not 

 known in any living form of this order, although this character is not unusual 



Piq. 65. Jawsof Vacelognathtit vagam Marsh; seen fro 



i be same spe< Lmen ; side view. 

 Fig. 67. — Tooth of Oeratodus guniheri Marsh. Natural t 



i abnve. < tnr halt nat 



in the carapace of many species, living ami extinct. Numerous remains of 

 the above species have been found in the Denver region, especially near 

 Morrison and ( Janyon. 



