274 C. SCHUCHERT MORRISON AND TENDAGURU FORMATIONS 



almost exclusively the only material so far found in this quarry . . . 

 [and it] was perhaps an upland form." ^' 



Of armored dinosaurs there were found single bones in more than 

 twenty places. In only two cases, however, were found great aggrega- 

 tions, one in the middle, the other in the upper dinosaur zone. The 

 richest place was at Kindope, in the middle dinosaur zone. Here occurred 

 the bones of about thirty armored dinosaurs of varying sizes, all closely 

 packed together and in horizontal position. There are almost no articu- 

 lating parts, only a few of the vertebrae remaining in association. There 

 is almost nothing of skulls (only back parts of three and a single tooth) 

 or of feet. All appear, according to the Berlin workers, to have been 

 stuck in the muds, killed in herds, and later, on the return of the tides, 

 washed on the shore as a bone-bed.^^ Again, the present writer holds that 

 this is evidence of river action rather than marine wave work. 



The habits of the dinosaurs, and especially of the sauropods, Janensch 

 thinks were only partly amphibious, similar to those of the living hippo- 

 potamus, for their feet show no modifications for swimming, but are like 

 those of other animals that have not abandoned walking over the dry 

 land. As for the habitats of the armored dinosaurs, there is as yet no 

 unanimity of opinion whether they are of the dry land or living mainly 

 in water. The dinosaurs, Janensch holds, were in the main land animals 

 and in their migrations over the tidal flats were killed catastrophically, 

 and therefore the place of their present occurrence is not their normal 

 habitat.^^ 



In the marine sandstones all of the mud was removed by the waves and 

 currents, as is the case in normal marine deposits along a deepening shelf 

 sea. The marine waters three times became deeper and passed over the 

 bars, invading the land more and more. Accordingly the work of the 

 waves was then more active and the assorting power greater. The marine 

 organisms thrived, and locally there were even coral reefs and areas of 

 oolite formation. Janensch thinks that the sauropods also waded around 

 in these marine waters, but because the bottoms were sandy and therefore 

 not sticky, as were the mud-flats of the dinosaur zones, they were not killed 

 and their bones did not get into the shallow-water marine sandstones. 

 The real reason for their absence seems to the present writer to be that 

 shore-dwelling sauropods did not live in marine waters feeding on marine 

 organisms, but rather that they were habituated to the fresh-water and 



^" O. A. Peterson : A mounted skeleton of Stenomylus hitchcocki, etcetera. Ann. Car- 

 negie Mus.. vol. 7, 1911, p. 268. 



38 Op. cit, part ii, pp. 258-259. 



39 Op. cit., part li, p. 247. 



