1918] Stock: The Pleistocene Fauna of Hawver Cave 



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Of the twenty-four species of mammals known from Hawver Cave, 

 twelve or half the number of forms present are extinct. The per- 

 centage of extinct species of Hawver Cave is thus relatively greater 

 than that of either Samwel Cave or Potter Creek Cave. 



A comparison of the faunas from the three principal caves of 

 California shows that Potter Creek Cave possesses the greatest number 

 of extinct genera, namely seven. Hawver Cave follows next with 

 six genera, while four extinct genera are known from Samwel Cave. 

 On this basis it would appear that Potter Creek Cave contains the 

 oldest mammalian assemblage with Hawver Cave approaching it 

 closely in age, while Samwel Cave is somewhat younger than either of 

 the other two. Three extinct genera are common to the three caves, 

 namely, Nothrotherium, Megalonyx and E uceratherium. The pres- 

 ence of the ground-sloth Mylodon and of a sabre-tooth tiger at Hawver 

 Cave is unique in that it records for the first time the occurrence of 

 these forms in cave deposits of California. The faunal differences 

 existing between Hawver Cave and Potter Creek Cave are to be 

 attributed in part to geographic separation of the deposits and in 

 part to a slight difference in age. 



The Hawver Cave fauna represents distinctly an older phase of 

 the Pleistocene than is indicated by the fauna from the Conard fissure 

 of northern Arkansas. It resembles more closely the fauna from the 

 Port Kennedy deposit of Pennsylvania and is more nearly related in 

 age to the latter than it is to the Conard fauna. 



During Pleistocene time the region about Hawver Cave was occu- 

 pied by a fauna consisting of forest and plains dwelling forms, just 

 as to-day the region is characterized to a certain extent by a mixture 

 of these types. The animals themselves have changed in the interim. 

 Within the Recent period wild horses, bison, mylodont sloths and 

 sabre-tooth cats are no longer ranging over this region and over the 

 Great Valley of California to the west. In the modern fauna, forms 

 typical of the plains are represented by the prong-horn antelope and 

 the dwarf elk. The absence of Orcamnos, the mountain goat, from 

 the Hawver Cave deposit indicates also that the fauna from this 

 locality came primarily under the influence of an environment such 

 as exists at the present day along the borders of the Great Valley 

 of California. E uceratherium, Megalonyx and Nothrotherium appear 

 to have been characteristic of the foothill belt of the Sierra Nevada 

 during Pleistocene time. 



