STORY OF THE DISCOVERIES 



HE first great fossil expedition in Wyoming was 

 conducted in the summer of 1870 in what is now 

 known as the Bridger Basin, near Fort Bridger. 

 An immense amount ot material was found at 

 that time by Professor O. C. Marsh and his expedition. He 

 obtained concessions from the Government and had an escort 

 of two companies of United States soldiers. The material 

 particularly searched for and found at that time was the bones 

 of the early horses, the ancestors of the modern horse. 



In the lowest horizon of the Tertiary, at the foot of the 

 Wasatch Mountams, was found a three and a four-toed horse. 

 Above, in a later age, were found the bones of the toes draw- 

 ing up, leaving one central toe. Many examples of this were 

 found; and, as the Professor worked toward the upper Pliocene 

 Tertiary, he found the horse as he is to-day with the exception 

 of the size. The earliest of the horses, the three and four toed, 

 were about as large as a fox. Several thousand feet higher in 

 the upper Tertiary the horse had taken his form of to-day, but 

 the size was not much increased; he was still small, a little larger 

 than a fox. In searching for these bones of horse? in which 

 Professor Marsh was particularly interested, the bones of many 

 other mammals were found, particularly camels, cats, dogs, bea- 

 vers, and deer. These bones were all carefully taken up and 

 shipped to the Yale Museum from Carter Station, on the Union 

 Pacific. Several similar expeditions were sent into this field in 

 the years from 1870 to 1877, and many wonderful discoveries 

 were made. Still other expeditions going into this field in later 



