THE LOWER EMBAR OF WYOMING AND ITS FAUNA 



E. B. BRANSON 



The University of Missouri 



About ten years ago Mr. N. H. Brown sent me a few Helodus 

 teeth from the Embar limestone near Lander, Wyoming, and 

 in the summer of 191 1 I had the good fortune to discover a rather 

 abundant fish fauna in the same region and on Bull Lake Creek. 

 In the former region the fossils occur about 25 feet from the bottom 

 of the formation and their vertical range is little more than 3 feet, 

 while in the latter they are found at from 35 to 38 feet from the 

 bottom. 



Blackwelder 1 and Woodruff 2 have reported two distinct faunas 

 from the Embar, the upper of which Girty 3 refers to the Permian, 

 but the fauna reported here is older and entirely distinct from the 

 other two. Collections from bottom to top of the Embar in several 

 localities show only one species common to the fish horizon and the 

 upper horizons. 



DESCRIPTION OF THE EMBAR LIMESTONE 



The Embar formation lies conformably, for the most part, 

 below the Chugwater formation on the eastern slope of the Wind 

 River Mountains and without apparent unconformity above the 

 Tensleep sandstone. In the Big Popo Agie region, near Lander, 

 it is about 400 feet thick, is largely limestone, and bears three and 

 perhaps more phosphate beds. The lowest bed is 23 feet from the 

 bottom, ranges from 1 foot to 5 or 6 feet in thickness, and bears 

 fish remains and Orbiculoidea utahensis in abundance. This bed 

 has been traced some 15 miles southeastward along the strike and 

 about 5 miles nothwestward. I have examined the same bed on 



1 Eliot Blackwelder, "New or Little Known Paleozoic Faunas from Wyoming 

 and Idaho," Am. Jour. Sci., XXXVI (1913), 177-79. 



2 E. G. Woodruff, "The Lander Oil Field," U.S. Geol. Sun., Bull. 452 (1913). 

 pp. 12-14. 



3 Ibid., p. 13. 



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