358 E. M. KINDLE 



Bone beds. — A considerable portion of the fossil remains of 

 vertebrate animals are found in "bone beds." 



The term ''bone bed" is in itself evidence of the tendency of 

 vertebrate-fossil remains to accumulate in certain restricted zones 

 and areas. Bone beds occur in each of the geological systems 

 from the Devonian up. Even the few vertebrate remains which 

 are known from the Ordovician may almost be said to represent a 

 bone bed because of their abundance in a single zone. The Middle 

 Devonian bone bed which forms the top of the Columbus limestone 

 in Central Ohio is a representative Paleozoic deposit of this type. 

 It has a thickness of 6 or 8 inches and consists of an "assemblage 

 of millions on millions of generally imperfect but mostly recog- 

 nizable organs or fragments of the bony structure of the forms of 

 fish life most characteristic of the Devonian age."' This bed 

 according to Stauffer^ can be traced across the northern half of 

 the state. 



In the Upper Devonian shales of northern Pennsylvania occur 

 numerous bone beds composed of the fragments of Catskill fishes. 

 These beds of fish fragments are apt to vary from a few inches 

 to a few feet in thickness and generally lie in the midst of beds which 

 are barren. 



The veteran collector C. H. Sternberg, who has probably 

 collected more vertebrate fossils than any other living man, appears 

 to have found the great majority of his fossils in bone beds. He 

 states that 



all through the Belly River series of rocks are bone beds. In some places I 

 secured hundreds, yes thousands of bones and teeth of many species, as well 

 as shields of sturgeons and the enameled scales of gar-pikes as perfect as if 

 picked up along a recent lake shore. There were also bones and shells of a 

 great variety of soft shelled turtles and others, with beautifully sculptured 

 shells; they range in size from less than six inches across to over two feet. 

 Crocodile bones and the dermal or skin plates of plated dinosaurs were common. 

 We secured hundreds of the pavement teeth of the ray Cope called Myledaphus , 

 also countless vertebrae of the reptile Champsosaurus? 



'J. S. Newberry, Monog. U.S. Geol. Surv., XVI (1889), 30. 

 ' C. R. Stauffer, Geol. Surv. of Ohio Bull. 10 (1909), p. 26. 

 * C. H. Sternberg, Hunting Dinosatirs (191 7), p. 84. 



