36 C. Schuchert — Dinosaurs of East Africa. 



harden and pack them ; many porters had to be secured to 

 carry the packages to the port, Lindi, where the bones were 

 boxed and sent to Berlin. It was a great undertaking in the 

 midst of malarial fevers, under very strange conditions, and in 

 a more or less tropical wilderness. At first they had 150 

 negroes, but later they employed nearly 500 ; throughout 

 the second working season they always had as many as 400. 



The hill Tendaguru, less than 100 feet high, lies isolated on 

 a high, thickly wooded plateau averaging about 650 feet above 

 the sea, and is the central point from which all of the diggings 

 have been operated. It is in the midst of an extensive dinosaur 

 cemetery, for at one time there were twenty exhumations in 

 operation scattered over 30 square kilometers, or across one 

 degree of latitude (between 9° and 10° S. and 39° and 

 39°30 / E.). The localities are shown on the accompanying 

 map. 



In a thickness of about 500 feet exposed along the stream 

 Mbenkuru are found three distinct horizons of soft shale with 

 dinosaur remains, separated from one another by hard coarse- 

 grained sandstones to conglomerates that have an abundant 

 marine invertebrate fauna. Each marine division has its own 

 assemblage of forms, and makes terraces along the river valley. 

 While the marine fossils have not yet been determined, still 

 Doctor Hennig states that the time represented is not of the 

 higher Cretaceous as was first supposed but of earliest or low- 

 est Cretaceous age, comparable to the earlier dinosaur horizon 

 of America, i. e., Morrison or early Comanchian (p. 48). All 

 of the beds are of one continuous series of deposits, as the 

 different horizons grade into one another. The conditions of 

 deposition therefore appear to have been an alternation of 

 exceedingly shallow marginal seas that came to be filled with 

 detritus and changed into great mud flats flooded by rivers and 

 possibly in part by high tides. Three such cycles are recorded. 

 Dinosaur bones do not occur in the marine deposits but begin 

 in the transition zones, where they occur with Belemnite 

 guards, and may be so abundant as to make bone conglomerates. 

 Where the bones occur in greater abundance there appear to 

 be no marine invertebrates. 



In the lowest dinosaur zone there is but little good material, 

 while the highest one is not at all so rich in remains as is the 

 middle division, out of which most of the bones and fossil 

 woods have been taken. One quarry was worked by many 

 negro laborers throughout the dry seasons of two years, so rich 

 in dinosaur remains are some of the places. In each of two 

 quarries at least fifty small individuals were huddled together, 

 not one of which retained a skull. At the base of the middle 

 dinosaur horizon is found a bone conglomerate made up of the 



