90 



TITANOTHEKES OP ANCIENT WYOMING, DAKOTA, AND NEBRASKA 



Washakie A is characterized by "rusty brown nodu- 

 lar sandstones," and Washakie B by "coarse white, 

 pink, and sabnon-colored sandstones" and by "the 

 extremely coarse green sandstones or feldspar con- 

 glomerates. The rocks first recognized as sandstones 



GEOLOGIC LEVELS OFSPECIES 



SUMMIT OF HAYSTACK M 



Zp^y\Eobas/7eus comufus, type 



"°?S-<5-v>.\ EobcLsileiLS- 

 ict)_i-s^E=^ Dolichorhimis 

 zone 



ZONAL LEVEL APPROXinATE 



Eomoropus amarorum, type 

 Lepforeodon marsh/, type 



\Do/ichorhinus hyoqnathus, type level 

 (A.M. No. 13164, Co/U906) 



'■ a.^i^?l%'^'^^^i^hMelarl>/nus earlei, type 



L£V£L OF 



S^r^ A my no don 



_=ti -"^ —^''^pnt/quas type 



ADOBE TOW/V 



Achaenodon insolens, type 



-■-'■'■ -~ '^-^M anleoceras washak/ensis, type level 

 Winlalherium speirlanum, type level 



Mesatirhinus megarhinus 



type 



Palaeosyops cope/ 



Manteoceras manteoceras 



type 



Uintafherium sp. div. 



Figure 62. — Columnar section of the Washakie Basin, Wyo. 



life zones 



Shows the principal genera of the lower and upper life zones and the actual level of certain characteristic species. 

 Chiefly after Granger (1909.1). This section includes the Uintaiherium zone (Washakie A), lower brown sand- 

 stones; Meiarhinus zone (Washakie B 1); and Eobasileus-DolichorMnus zone (Washakie B 2) , upper gray-green 

 beds. ' Numbers in column show position of lithologic specimens examined by Johannsen. 



prove to be interspersed with dacite and glass tuffs." 

 (Johannsen, 1914.1, p. 215.) The sandstones, which 

 were derived from granite by erosion, consist of grains 

 of quartz, hornblende, and feldspar embedded in a 

 shghtly devitrified groundmass. (See PI. IX.) 



The composition of these sediments indicates the 

 presence in this region of active volcanoes, which 

 were discharging great clouds of dust. Unlike the 

 sediments of the Bridger Basin the sediments of the 

 Washakie Basin were deposited in rather turbulent 

 water and contain none of the 

 "white layers" that indicate 

 the still water that prevailed 

 in the upper Bridger. Turbu- 

 lent water is not favorable 

 to the preservation of the 

 remains of small mammals. 

 Only one of the smaller 

 perissodactyl ungulates 

 (Triplopus) has been found, 

 and no remains of Equidae. 

 The first aquatic rhinoceroses 

 {Amynodon) belong to a river- 

 frequenting type; the first of 

 the entelodonts {Achaenodon) 

 is also a river-frequenting 

 form; the first of the forest- 

 dwelling chalicotheres {Eomo- 

 ropus) also occurs. Thus the 

 Washakie Basin has preserved 

 for us mainly the larger 

 swamp and river-border fauna 

 but has yielded little record 

 of either the arboreal or 

 plains -living cursorial fauna 

 of the time. 



In the fauna of the Wa- 

 shakie Basin (a list of which 

 is given in the table on p. 89) 

 the large hoofed animals pre- 

 dominate, especially those 

 adapted to stream borders, 

 swampy land, rivers, and 

 streams. A small fauna of in- 

 sectivores, lemuroids, carni- 

 vores, and ancestral artiodac- 

 tyls doubtless abounded, but 

 the environment was unfavor- 

 able to the preservation of 

 such remains, and the micro- 

 fauna has been found only 

 rarely. The small titanothere 

 MetarUnus is highly distinc- 

 tive of this Washakie B 1 life 

 zone. (Kiggs, 1912.1.) 



Uinta .B.— Exactly the 

 same physiographic condi- 

 tions prevailed at the same time in the great basin 

 south of the Uinta Mountams while the sediments 

 known as Uinta B were being deposited. These sedi- 

 ments, which have a combined thickness of 800 feet, 

 contain exactly the same riparian fauna, including a 



35), showing 



