56 CEKOZOIC MAMMAL HORIZONS 



FauniMic separation from western Europe in the upper Eocene. 



Order. 



Families 

 peculiar to 

 Europe. 



Families 

 commoii 



to west4em 

 Europe 



and Xorth 

 America. 



Families 

 peculiar to 



North 

 America. 



Ad r. iTpc>da 







1 



i 



0 

 4 



3 



Ili=«Tivora 



(?) 



1 

 0 



CreC'donta 





2 

 1 

 0 

 6 

 1 



RCKieiiTia 



Camivora 



0 



2 



Aitiodactyla 



Penssodactrla 



Charoptcra 



1 n 



4 





Thus in the later Eocene of the Mountain Region (rirdathenum, 

 Eohasilem, and Dipheodon zones) there are onl^- 4 or 5 families in 

 common with Europe out of a total of 28 to 30, whereas in the succeed- 

 ing Oligocene Mountain and Plains regions (see p. 59) there are 21 

 families in common with Europe out of a total of 48. 



The entire Uinta Basin deposition, as first fully explored by the 

 American Museum expedition under Peterson,^ overlaps in time 

 both the upper Bridger and the entire " Washakie" deposition: thus it 

 begins (Osbom i contemporaneously with the uppermost portion of the 

 Bridger, is equivalent to the entire ^'Washakie, ' and then continues 

 after the close of the '' Washakie" into the Uinta (Z>?j>?(7^<x7o7? zone, 

 ''true or upper Uinta '').^ Its sparsely known manimaUan fauna <^ 

 is as follows: 



Summary of genera. 



Archaic Cretaceous maTnTnals 6 



Modem or Tertian.- Tiiammalft 27 



The term Uinta formation (Marsh and King) is confined to the 

 upper beds, or Diplacodon zone (*'true Uinta")- 



PROVTSIOXAX FAUNAL LEVILLS. 



C. Uinta formation, 600 feet. Diplacodon zone. Distinguished 

 by absence of Dinocerata : presence of Canidse. 



B. Middle beds of Uinta Basin, later Eocene. 350 feet. EohasUeus 

 zone. Contains among Amblypoda-Dinocerata, EohasUeus (generic 



« Osbom. H- r., FossQ mammals of the Uinta Basin, etc : BtilL Am- Mas. Xat. Hist., toL 7, 1885, 

 pp. 71-105- 



& This "troe Uinta" fauna was that wiucti was first detennined and described by Harsli in 187a 

 The ondedying Vintatherium and EobatUeu* faonse were first discovered by Peterson in 18d4 and 

 descxibed by the writer. 



f Scott, W. B., and Osbom. H. F., The Mammalia of the Uinta formation: Trans. Am. Philos. Soc, 

 n. s., ToL 16, 1689, pp. ^l-S?2. 



