4 Zoology of Colorado 



and evidences of it may be seen everywhere. East of the front 



range, there are exposures of Cretaceous rocks, belonging to a 



period when the country was at sea-level, and the foothills of 



today were represented by a sea-coast. Subsequently the land 



was elevated, and during Tertiary times many strange animals 



roamed over the plains. Deposits were formed along the river 



valleys, containing their bones. Continued erosion has very largely 



washed these away, but in places, as at Pawnee Buttes, a large 



section has been left undisturbed, the streams passing on either 



side. In such localities the student searches with success for 



evidence of the life of the past; while he readily imagines, by 



mentally continuing the horizon represented by the tops of the 



buttes, the enormous amount of material washed away, with it of 



course innumerable fossil remains. It was in the vicinity of 



Pawnee Buttes, in Weld County, that a party from the Colorado 



Museum of Natural History obtained, not very long ago, a fine 



series of the bones of large extinct mammals, including a kind of 



rhinoceros. A ranchman had been digging post holes, and chanced 



to throw out a fragment of bone, which at once suggested further 



investigation. Yet this clue would have meant nothing, would 



have led to nothing, had not Mr. Figgins and his colleagues of the 



museum noted the find, and proceeded to take advantage of their 



opportunity. They were fortunate in that the deposit was easy 



of access. Near Troublesome, in the mountains of Colorado, 



a well preserved fragment of the jaw of a fossil horse (Parahippus) 



was found in boring for a well. It is almost certain that other 



remains, certainly the rest of the broken jaw, are still buried in 



that locality. It may be that thirty feet underground there is a 



series of bones comparable to that obtained in Weld County. We 



do not know; but no one has the time or means to investigate. 



The bones referred to are of course large and conspicuous, 

 once uncovered. Other fossils, no less interesting, require keen 

 eyes for their detection. One day Mr. J. T. Duce was walking in 

 Lesser's brickyard, at Boulder. The rock there is Pierre Cretaceous, 

 deposited in the sea, not far from the shore. He picked up a small 

 piece of rock, containing a fragment of a marine shell, and saw in 

 it what looked like the tip of an insect wing. The exposed piece 

 was so small that few would have noticed anything at all; but 

 when the fossil was carefully chipped out it proved to be the wing 



