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Prof. 0. C. Marsh — Classification of Dinosaurs. 



Genera Stegosanrus (Hi/psirltophns), Diracodon, f DystropTi&us, 

 Palceoscincns, Priconodon, all from North America ; and in Europe, 

 Omosaurus, Owen. Jurassic and Cretaceous. 



(2) Family Scelidosauridte. Neural canal narrow ; diapophysis 

 of dorsal vertebras supporting head and tubercle of ribs. Astragalus 

 not coossified with tibia; metatarsals elongated; three functional 

 digits in pes. 



Genera Scelidosaurus, Acanthopholis, Hylaosaurus, Polacanthns. 

 Jurassic and Cretaceous. Known forms all European. (Figure 6.) 



^^n^^O 



Fig. 6. — Scelidosaurus Harrisoni, Owen. 



■^ 6 -. Jurassic, England. 



Bones solid. 



(3) Family Kodosanridce. Heavy dermal armour. 

 Fore limbs large ; feet ungulate. 



Genus Nodosaurus. Cretaceous, North America. 



Sub-order Ceratopsia (Horned face). 



Premaxillaries edentulous ; teeth with two distinct roots ; skull 

 surmounted by massive horn-cores ; a rostral bone, forming a sharp, 

 cutting beak ; expanded parietal crest, with marginal armature ; ? a 

 pineal foramen. Vertebras and limb bones solid ; fore limbs large ; 

 femur longer than tibia ; feet ungulate ; locomotion quadrupedal. 

 Dermal armour. 



Fig. 7. — Triceratops prorsus, Alarsk. 



Cretaceous, AYvominj: 



(4) Family Ceratopsidce. Anterior cervical vertebras coossified 

 with each other ; posterior dorsal vertebras supporting on the 

 diapophysis both the head and tubercle of the rib ; lumbar vertebras 



