HISTORICAL REVIEW OF THE LARAMIE PROBLEM. 



29 



forms, and hence these beds were regarded as 

 of Fort Union age. 



For more than a decade after the studies 

 resulting in the last-mentioned paper little or 

 no active geologic work was done in the 

 Converse County area, though the collecting 

 of the remains of huge dinosaurs was continued 

 from time to time by several persons. In the 

 meantime, however, it had become known that 

 the ceratopsian. dinosaurs that were so abund- 

 ant and characteristic in the Converse County 

 region were by no means confined to that area. 

 In 1907 Barnum Brown, of the American 

 Museum of Natural History, published a short 

 paper 3 in which he recorded their abundant 

 presence at many localities in Montana. This 

 discovery was made in 1901 by William T. 

 Hornaday, director of the Bronx Zoological 

 Garden, New York, while hunting in the bad- 

 lands along Missouri River north of Miles City. 

 Here Dr. Hornaday found a number of large 

 bones, one of which was brought home and 

 proved to be the tip of a horn of the large 

 dinosaur Triceratops., From 1902 to 1906 

 Brown was engaged in exploring and collect- 

 ing in Montana. The principal locality was 

 in the vicinity of Hell Creek, a small stream 

 entering the Missouri about 155 miles northwest 

 of Miles City, but the same dinosaur-bearing 

 beds were found on Yellowstone River at 

 Castle Butte, near Forsj^th, at Glendive, at 

 Ekalaka, and at Hocket post office, from 

 which they were thought (and have since been 

 proved) to be continuous with similar dinosaur- 

 bearing beds on the little Missouri and near 

 Grand and Moreau rivers in South Dakota. 



The dinosaur-bearing beds on Hell Creek, 

 named the "Hell Creek beds" by Brown, are 

 described as resting unconformably on Fox 

 Hills beds of varying thickness, while above 

 and representing an uninterrupted continua- 

 tion of them is a lignite series referred with 

 question to the Fort Union. Above this series 

 is the unquestioned Fort Union with a" char- 

 acteristic flora. Tn discussing the correlation 

 and age of the "Hell Creek beds" Brown wrote 

 as follows; 



, Lithologically the Hell Creek beds of Montana are similar 

 in almost every respect to the Ceratops beds of Converse 

 County, Wyo. Most genera and many species of verte- 



• Brown, Barnum, The Hell Creek beds of the Upper Cretaceous of 

 Montana: Am. Mus. Nat. Hist. Bull., vol. 23, p. 823, 1907. 



85344—22 3 



brates and invertebrates are common to both deposits, 

 while the f aunal facies may be considered a unit. * * * 

 They are therefore considered of contemporaneous depo- 

 sition. 



In regard to the age of these beds he said: 



Strictly following King's definition of the Laramie, 

 neither of these deposits can be considered as such, for 

 neither one represents a continuous sedimentation from 

 the marine Fox Hills. They should therefore be grouped 

 with the Livingston, Denver, and Arapahoe beds and may 

 be considered post-Laramie. 



Although Brown considered the "Hell Creek 

 beds" as post-Laramie and thus comparable 

 to the Arapahoe and Denver formations in posi- 

 tion, it is evident from the title of his paper 

 that he still regarded them as Cretaceous. 



The year 1907 was also marked by the pub- 

 lication of the monograph on the Ceratopsia by 

 Hatcher and Lull. 4 This comprehensive treat- 

 ise was mainly the work of Hatcher and had 

 been nearly completed at the time of his death, 

 July 3, 1901. It was compiled and edited by 

 Lull, who added a chapter oh the phylogeny, 

 taxonomy, distribution, habits, and environ- 

 ment of the Ceratopsia. From this it appears 

 that the localities then known for the so-called 

 Laramie Ceratopsia were Black Buttes and 

 Converse County, Wyo., and Hell Creek, Mont. 

 The Denver localities were considered under a 

 separate heading, and the statement was made 

 that these beds (Arapahoe and Denver) had 

 been "considered to be of post-Laramie age." 

 It was of course held that all the localities 

 which had afforded the "Laramie Ceratopsia" 

 belonged to the Cretaceous. 



In 1905 the United States Geological Survey 

 began an investigation that had for its object 

 the classification of the coal lands in the 

 public-land States of the West, and this work 

 has been continued until the present time. 

 The plan has been to send a party, usually a 

 small one, to survey a definite area for the 

 purpose of ascertaining its coal resources and 

 incidentally of procuring such data as time and 

 opportunity offered on the general geology of 

 the area. In this manner a large and impor- 

 tant body of facts has been accumulated 

 regarding the geology of regions or localities 

 that might otherwise have remained obscure 

 or imperfectly known for an indefinite period. 



* Hatcher, J. B., and Lull, E. S., The Ceratopsia: TJ. S. Geol. Survey 

 Mon. 49, 1907. 



