7 
Relationships of the Fauna 
As is noted under the discussion of individual species, the Upper 
Devonian fauna is closely related to that of the Upper Devonian Ouray 
limestone as described from Colorado and New Mexico . 1 It also contains 
many species in common with the Three Forks formation of Montana as 
described by Haynes . 2 * 
The Mississippian fauna has a remarkably large number of species 
identical with those of the Kinderhook of the Mississippi valley.* This is 
especially true of the species from the Banff shale, but those from the 
Mississippian part of the Bundle limestone show a more decided Burlington 
affinity. This distinction appears to be true only in a general way, for the 
majority of species in the basal beds continue into the highest ones. The 
Mississippian beds also contain, mingled with the preceding, a few elements 
characteristic of the Keokuk and Warsaw formations of the east. The 
fauna is thus very similar to that of the Madison limestone of Wyoming 
and Montana as described by Girty from the Yellowstone National park . 4 * 
What was formerly called Pennsylvanian in this region is distinctly 
separated into an upper and a lower part, both lithologically and faunally. 
The fossils in the upper strata, the Rocky Mountain quartzite, are most 
noticeably different from those in the lower beds, the Rundle limestone. 
The majority of the species in both are also present at the similar horizons 
throughout much of North America. The upper, the fauna of the Rocky 
Mountain quartzite, is here characterized by such Permian species as 
Euphemus carbonarius var., Plagioglypta canna, and Bahewellia parva. 
Only two of the species found here occur also in the Lower Pennsylvanian 
of this region — Produetus coloradoensis ? and Spirifer rockymontanus. 
Confined to the lower horizon are such characteristic Pennsylvanian species 
as Lophophyllum profundum r Campophyllum torquium, Produetus cora y 
Pustula punctata y and Spirifer cameratus. With these occurs also a most 
noticeable Mississippian element consisting especially of three species of 
Lithostrotion, Hapsiphyllum calcareforme't y Syringopora aculeata , and Reti- 
cularia setigera . All these species are very abundant here; they are not 
represented by a few decadent individuals but were evidently thoroughly 
acclimated to their Pennsylvanian environment. The early Pennsylvanian 
aspect of these faunas is further emphasized by the presence of some 
species (such as Composita ozarkana and Dielasma arkansanum ) described 
by Mather 6 in basal Pennsylvanian beds from Arkansas and Oklahoma. 
GEOLOGICAL HISTORY OF THE REGION 
The history of this region, so far as the rocks of our section are con- 
cerned, began with the submergence of the entire area beneath the sea 
during Cambrian time, as attested by the marine fossils, including an 
abundance of trilobites, in the sediments of the Castle Mountain group. 
If the Upper Ordovician and the Silurian were periods of deposition for this 
i Girty, U.S. Geol. Surv., 20th Ann. Rept., pt. 2, 1900, p. 31. 
Kindle, E. M., U.S. Geot, Surv., Bull. 391, 1909. 
* Annals Carnegie Mua., vol, 10, 1916, p. 13. 
* Weller, "Mississippian Brachiopoda," Illinois Geol. Surv., Mono. 1. 
4 U.S. Geol. Surv., Mono. 32, pt. 2. 
* "The Fauna of the Morrow Group of Arkansas and Oklahoma/ 1 Bull. Sci. Lab. Denison Univ., vol. 18, 1915, 
pp. 59-284. 
