ORDER YIII 



DINOSAUKIA 



■i-i'.i 



relatively very large and delicate. Nasal bones long, fused, and supporting a 

 large median horn-core ; prefrontals laterally swollen and partly overhanging 



.1 



B 



Fig. 32S. 



Ceratosaurus nasicornis, Marsh. Upper Jura; Colorado. Skull from anterior (J), and lateral (7;), aspects, 

 1 ;,. A, Orbit ; D, Antorbital vacuity ; D', Mandibular vacuity ; N, External nostril ; S, Suprateinpora! vacuity ; 

 (after Marsh). 



the orbits, which are inferior in size to the lateral temporal vacuities. 

 Cervical vertebrae strongly opisthocoelous, flattened in front. Tail long, 

 compressed and deepened in its anterior portion, as indicated by the long 



neural spines and chevron bones. Pelvic elements 

 fused at the acetabulum ; pubic and ischial sym- 

 physes expanded. Fore - limbs very small, and 

 manus with four digits (i-iv) each bearing a claw. 

 Femur much curved ; astragalus not fused with 



the tibia, but bearing a large 

 ascending process. Digits 

 Xos. I and v wanting in the 

 hind foot ; metatarsals fused 

 together (pathologically 1) 

 and with the distal tarsals. 

 Dermal ossifications observed 

 in the neck region. Upper 

 Jura ; Colorado. C. nasi- 

 ^A comis. Marsh. 



Ceratosav/rus nasicornis, Marsh. 

 Upper Jura ; Colorado. Restora- 

 tion of skeleton, 1/40 (after Marsh). 



*V^ 



Allosaurus, Marsh (Fig. 330). Skull unknown. Vertebrae and appen- 

 dicular skeleton resembling Ceratosaurus, except that the pelvic elements and 

 metatarsals are not fused. Upper Jura ; Colorado. 



Labrosaurus, Marsh. Upper Jura ; Colorado. Streptospondylus, v. Meyer, 

 Upper Jura ; Northern France and England. 



Megalosaurus, Bucklarid (Poikilopleuron, Deslong.), (Fig. 331). Teeth with 



