INEQUALITIES OF SEDIMENTATION 359 



C. M. Sternberg states that he knows of "no less than 7 bone 

 beds in which only horned dinosaurs are represented.'" Bone 

 beds are frequently referred to in paleontological papers as 

 "quarries." Concerning some of these quarries in Alberta 

 Barnum Brown writes as follows: 



Frequently remains of many Trachodonts are found massed together in 

 quarries, probably as a result of water action, in the Belly River and in the 

 Edmonton strata, and there are two records of such occurrence in the Lance. 

 In such quarries it is not exceptional to find Trachodonts , carnivorous dino- 

 saurs, Ceraiopsia and other remains commingled, although Trachodonts 

 usually predominate.^ 



Various explanations have been offered for these aggregations 

 of vertebrate remains, each of which is probably applicable 

 to certain cases. Suffocation and burial by sand storms of the 

 "frightened multitudes which had herded together in search of 

 safety or courage" is a hypothesis oft'ered by C. H. Sternberg.^ 

 Land vertebrates living in a wide alluvial plain might be periodi- 

 cally surrounded and herded together and drowned on the highest 

 parts of an extensive area. In some instances prairie or forest 

 fires may have been the compelling force which drove multitudes of 

 land vertebrates into lakes and rivers. The fondness of most 

 mammals for salt leads them, as is well known, to visit saline 

 springs, and where these springs are in the midst of boggy ground 

 may result in such aggregations of bones as those of the famous 

 Bone Lick of Kentucky. Sir Charles LyelP suggested still another 

 way in which great numbers of large vertebrates may sometimes 

 be drowned in lakes and rivers. He states that "It is well known 

 that, during great droughts in the Pampas of South America, the 

 horses, cattle, and deer throng to the rivers in' such numbers that 

 the foremost of the crowd are pushed into the stream by the pressure 

 of others behind and are sometimes carried away by thousands 

 and drowned." 



' Letter to the writer, January 7, 1919. 



= Bull. Amer. Mus. Nat. Hist., XXXVII (191 7), Art. X, pp. 282-84. 



5 Sternberg, Life of a Fossil Hunter (1909), p. 132. 



■• Sir Charles Lyell, Travels in North America in the Years 1841 and 1842, pp. 

 141-42. 



