^76 



C. SCHUCHERT MOKitlSON AND TENDAGURU FORMATIONS 



"During the time from the oldest Dogger [= early Jurassic] to the end of 

 the Lower Cretaceous, German East Africa was at no time completely out of 

 the water." "The lowest deposits of the Tendaguru series, including the two 

 lower dinosaur beds, belong in the Upper Jurassic/' 



As the Trigonia schwarzi zone is N'eocomiaii, the Berlin authorities are 

 agreed that the npper dinosaur zone is also Lower Cretaceous — a con- 

 clusion that need not necessarily follow. 



Correlations on basis of dinosaurs. — Janensch"^^ states that the African 

 two upper dinosaur faunas show remarkable similarity with the Morrison 

 fauna. This is seen in that in both regions the Sauropoda are of first 

 importance^ and with these are associated armored dinosaurs (but not 

 stegosaurians), small to medium-sized Ornithopoda, and small mammals. 

 There is, however, a greater variety in America, and, the present writer 

 will add, a complete absence of all marine evidence, while there are present 

 many fresh-water and pulmonate shells. The generic relationships of the 

 dinosaurs, Janensch states, can not yet be indicated, though it seems that 

 Brachiosaurus occurs in both areas. The Wealden dinosaurs, of pre- 

 sumably later or younger age, are far less closely related, so that the f aunal 

 kinship is decidedly with the United States. The Morrison, he believes, 

 is, in any event, "transitional from the Jurassic to the Lower Cretaceous, 

 and in this agrees very closely with the African saurian beds." This is, 

 however, an assumption that needs confirmation, though the same state- 

 ment has also been made by American vertebratists. 



In tabular form Janensch's correlations are as follows : 



Lower Cretaceous 

 Aptian 



Makonde series. Marine north of Tendaguru area 



m 



% 



OS 



Lower Cretaceous 

 Neocomian 



Trigonia schwarzi marine sandstones 



Upper dinosaur friable limy-sandy shale (Wealden) 



Upper Jurassic 

 Malm 



Trigonia smeei marine sandstone 

 (Upper Kimmeridge-Tithonian) 



Middle dinosaur friable limy-sandy shale 

 (Kimmerldge) 



Nerinea marine sandstone 



Lower dinosaur friable sandy marl 



rxact age not yet 

 established (II, 

 page 237) 



Granite and gneiss 



*3 Janensch : Op. cit., part ii, pp. 84-85. 



