TENBAGURU SEHIES 269 



(2) Upper or third dinosaur zone. Limy-sandy marls. About 40 meters. 



This is the most widely exposed zone of the Tendaguru. 



Gray sandy marl, 2 meters. 



Usually intensely red sandy marl, 5 meters. 



Light yellowish gray, very soft sandstones, with zones of sandy 

 marls, 10 m. 



Red sandy marls rich in clay, 2 m. 



Yellowish gray soft sandstone, 1.5 m. 



Red sandy marl rich in clay, about 5 m. 



Gray and reddish sandy marl, about 4 m. Has saurians. 



Gray sandy marl with occasional interbedded sandstones and a 

 basal red layer, about 5 m. Has saurians. 



Transition zone. Gray sandy marls that often pass into soft 

 sandstones with local accumulations of bones, and occasionally 

 with marine fossils, as belemnites, 3 meters thick. 

 The following Sauropoda occur in this zone: Gigantosaurus afri- 

 canus (most closely related to American Diplodocus), G. ro- 

 bustus, Brachiosaurus brancai (this genus also in the Amer- 

 ican Morrison), B. fraasi, Dicrwosaurus sattleri (this genus 

 seems to be closely related to Brontosaurus and Diplodocus). 

 Here also are armored dinosaurs related to the Wealden Omo- 

 saurus and Polacanthus, and, rarely, Theropoda. Isolated 

 crocodilian teeth, along with those of selachians (Orthacodus) 

 occur near the base of this zone, and here are remains of the 

 ganoid Lepidotus minor, a Wealden form. Fresh-water snails 

 are very rare. Fhysa tendagurensis was found associated with 

 Mytilus cf. galliennei and Cyrena. At the base of the zone 

 Gyrena occurs in colonies. A fruit from this zone is regarded 

 by Potonie as of Wealden age. 



(3) Middle marine sandstones with Trigonia smeei. About 20 meters 



thick. (Hennig states that over a wide area occur more or 

 less large lenses of oolite formations that In one place attain a 

 thickness of 60 meters (page 17). These oolites hold the posi- 

 tion here indicated.) 



Soft, fine-grained, olive-colored (when weathered) sandstone, Im. 



One bed of light-colored, hard, limy sandstone that is coarse- 

 grained to conglomeratic. Has flat and rounded feldspars up 

 to several centimeters long. 1 m. 



Soft yellowish sandstones, 4.5 m. 



One hard, gray, fine-grained, limy sandstone with small well- 

 rounded pebbles of quartz, 0.5 m. 



Grayish yellow, thin-bedded, somewhat slaty, fine-grained, limy 

 sandstone, 5 m. 



Hard, gray, coarse-grained, limy sandstone with larger well- 

 rounded quartz and feldspar pieces, 0.25 m. Toward southeast 

 changes into an oolite. Rich in fossils, and particularly in 

 thick-shelled mollusks and corals. Trigonia smeei especially 

 common. 



Yellow soft sandstones, 8 m. 



