298 



H. r. OSBORN JURASSIC-CRETACEOUS TIME 



long elapsed, nameh', after the long Wealden stage, there occurs a great 

 earth movement, and the succeeding Cretaceous stages are deposited hori- 

 zontally on the shai"ply upturned basal Cretaceous, or Wealden. 



This is clearly shown in the accompanying figure (figure 1), repro- 

 duced from Haug.^ 



FiCtRK 1 



Cretaceous. 



Upper 

 Jurassic 



6. 



5. 

 4. 



o 

 O. 



S 6 



—Relatiotix of the Jiirassir (1-H) nnd the Cretaceous (6-10) in Wiltxhire, 

 Evfilnnd. (After 11. P.. Woodward and K. Hang) 



10. Turonian. 

 9. Cenomanian (= Base of Upper Cretaceous). 

 8. Albian. 

 7. Aptlan. 



(Great diastrophic movement, causing angular unconformity.) 

 Wealdian. Iguanodonts more specialized than tliose of the Morrison. 

 Purbeckian. Mammals similar to those of the Morrison. 

 Portlandian. 



Kimeridgian. Iguanodonts similar to those of the Morrison. 

 Lusitanian. 



Oxfordian. Marine invertebrate life similar to that of the Sundance. 

 Sauropoda similar to the most primitive forms of the Morrison. 

 Toothless ichthyosaurs, OiJthalmosaiinis, similar to the Sundance 

 Baptanodon. Vertebrate and marine invertebrate fauna correlated 

 with that of the SiiiKhinrc, which is referred by Stanton (1909) to 

 the lower part of the Upper .Jurassic. 

 (Callovian.) 



Faun'a and Fl01!A 



Xow, let us examine more closely the European stages and their fauna. 

 In the classification of D'Orbigiiy the last stage of the Jurassic system 

 was designated under the name Portlandian, derived from Brongniart. 

 "This," observes Haug {op. cit., page 1075), "can be extended to the 

 upper Oolithic group by comprising within it the Purbeckian, wliicli is 

 simply a brackish facies of the superior portion of the Portlandian stage 

 and Avhich varies in thickness in different regions." Beneatli the Poit- 

 landian is the Kimeridgian, beneath the latter the Lusitanian , and be- 

 neath this again the Oxfordian. It is in tlie Oxfordian that the earliest 

 Sauropoda of the ty])e of Cetiosaurus occur in Europe, a type of dinosaur 

 which is in a stage of evolution similar to that of the Haplocaniliosaurus 

 of the Morrison of Caiion Citv, while within the Kimeridgian is found 

 a species of iguanodont dinosaur known as Caniptosaurus pvestividii, 

 which is very similar {teste Gilmore) to the Caniptosaurus nanus of the 

 Morrison: in fact, all the camptosaurs of the Morrison are more gen- 

 eralized and primiti\e in structure than the iguanodonts of the "Wealden. 



- E. Haug : "Traite do Oeologie, vol. ii, Les Periodes geologiques." 

 Colin, Paris, 1908-1911, p. 1187. 



8vo. 



Armand 



