Features in History of Life on Pacific Coast 



Faunas of Pleistocene Caves. — ^A number of 

 important discoveries of rich mammal-bearing Ple- 

 istocene deposits have been made in caverns situ- 

 ated in the limestone regions of the mountains of 

 northern and eastern California. The faunas ob- 

 tained in these caves have contributed much to our 

 understanding of the history of mammalian life on 

 the Pacific Coast. 



Potter Creek Cave, in Shasta County, furnished a 

 fauna comprising more than fifty species, of which 

 approximately one-half are extinct. Included in 

 this fauna are the great bear Arctotheriiim, a bear 

 of more modern type related to the black bear, a 

 puma, a large extinct lion, an extinct wolf, and frag- 

 mentary material representing the deer, mountain 

 goat, ground sloth, bison, camel, mastodon, elephant, 

 extinct horse, and a goat-like animal known as 

 Euceratherium. Samwel Cave, also in Shasta 

 County, contained a fauna differing to some extent 

 from that of Potter Creek Cave. The great bear is 

 absent, and there is present another peculiar goat- 

 like animal known as Preptoceras. 



Hawver Cave near the town of Auburn, on the 

 overland line of the Southern Pacific Railway, was 

 discovered by the late Dr. J. C. Hawver, through 

 whose interest much material of scientific value has 

 been brought to light. The collections from this 

 locality comprise a number of extinct mammalian 

 forms, but investigation of the fauna as a whole has 

 not been completed. 



Rancho La Brea. — The deposits of fossil skele- 

 tons in the Pleistocene asphalt beds of Rancho La 

 Brea constitute one of the most interesting features 

 in the history of life on the Pacific Coast. The 

 unusual nature of the accumulation, the vast quan- 

 tity of material, the marvelously perfect preserva- 

 tion, and the great variety of life represented all 

 serve to mark this localit}^ as one of the most im- 

 portant occurrences of remains of the life of a past 

 period known in America. The site of the excava- 

 tions is about seven miles from the middle of the 

 citv of Los Angeles and is within a stone's throw of 

 Wilshire Boulevard, a fine automobile road between 

 Los Angeles and Santa Monica. The locality can be 

 reached by automobile in twenty minutes from the 

 central part of the city. 



The bones are found at Rancho La Brea in 

 asphalt pits or chimneys which are the vents 

 through which oil and gas have escaped from great 

 reservoirs of oil located far below the surface. The 

 geologic history of this region indicates that bend- 

 ing or breaking of the strata has permitted the oil and 



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