TENDAGURU SERIES 271 



Gray, limy sandstone with undecomposed feldspars and plant 



remains, or an arenaceous limestone with fossils. Locally 



Nerineids. 

 One bed of hard, gray to brownish gray, limy sandstone with 



scales of graphite and light and dark mica. 

 Fine-grained gray limy sandstone with an abundance of foreign 



(conglomeratic) clay and clay-sandy inclusions. 

 Soft, yellow, thin-bedded sandstones that are fossiliferous at the 



top. 

 The following described species occur in this zone, those in italics 



being regarded as guide fossils : 

 Cephalopoda: 6 species. Nautilus sattleri, N. latifrons (new), 



Haploceras priscum (new), Perisphinctes sparsiplicatus, P. cf. 



achilles, P. staffi (new). 

 Gastropoda: 8 species. Patella, Lissochilus, Natica, Ampullina, 



Pseudomelania (Oonia), and Nerinella credneri (comes from 



below and is also present in the higher T. unieei zone). 

 (G) Lower or first dinosaur sandy marls. Thickness over 20 meters. 



Gray and red sandy marls devoid of lime. Has very small 



dinosaur bones and rarely Cyrena. Actual contact with granite 



and gneiss obscured. 



CONCLUSIONS AS TO HABITS AND HABITATS OF AFRICAN DINOSAURS 



In the lowest dinosaur horizon, which Branca refers to "the end of 

 Jurassic time," the saurians are said to be "very small animals." That 

 is all that we know of them as yetl In the middle and upper zones, 

 which he states pass in age from the Jurassic to the Lower Cretaceous, 

 the sauropods attained great size and Brachiosaurus hrancai was the 

 largest of all known land animals, certainly exceeding in weight and 

 stature the Amevicsin Brontosaurus and Diplodocus. The skull is about 

 the size of that in Diplodocus, but as the skeleton is not yet mounted the 

 dimensions cannot be given. The femur attains to 9 feet (2.8 m.) in 

 length. Branca believes that these animals attained great age, and their 

 bones became more solid with growth. Because of the small head and 

 consequent small eating apparatus, they must have subsisted, relative to 

 their great size, on small amounts of food. It may be that they got more 

 nourishment and lime for their skeletons out of v^hat they ate than is 

 usually the case in animals, and to this faculty may be due their size. In 

 this connection Branca says :^^ 



"We will probably come nearest the truth if we assume not one cause, but 

 rather a number of circumstances, that led to the great size of the Sauropoda : 

 great age combined with a long growth period; also very great powers of 

 digestion and assimilation of the food ; and that these in connection with slug- 

 gish habits led to the economy of the food materials." 



33 Op. cit., part I, pp. 76-78. 



