I \ 0L\ TIOA OF I HE HORSE 103 



Si »i mi. \-i Wing 



HALL OF THE AGE OF MAMMALS 

 FOSSIL MAMMALS OF THE TERTIARY PERIOD 



The particular feature of this hall is the wonderful series in thees 

 by the entrance and in the first alcove on the right showing the evolution 

 Evolution of the horse in nature. The Museum is justly proud of this 

 of tne collection. \<>t only is it the largest and finest serii 



rse fossil horse skeletons in the world, but it is larger than the 



combined collections of all other institutions, and it contains the 

 earliest known ancestors of the horse, the little four-toed Eohippvs, 

 which was no bigger than a fox and on four toes scampered over 

 Tertiary rocks. As will be seen by an examination of the skeletons 

 of the horse and man, the modern horse walks on the tip of his middle 

 finger and toe. The front hoof bone corresponds t<» the last joint of 

 the third finger in the human hand, and the other bones of the leg corre- 

 spond bone for bone with the structure of the finger, wrist and arm of 

 man. The similarity in structure of the skeletons of horse and man 

 is brought out in the exhibit of a rearing horse being controlled by 

 man. A comparison of these two skeletons will show that although 

 very different in proportions the bones of the one correspond with the 

 bones of the other. In the modern horse the remaining fingers or toes 

 of the fore and hind foot have entirely disappeared, or remain only as 

 vestiges, the so-called " splint bones." The structure of the modern 

 horse shows that it developed from a five-toed ancestor. This ancestry 

 has been traced back to the four-toed stage. [See Guide Leaflet No. 36. 

 The Evolution of the Horse.] 



In the wall case at the right of the entrance is given a synopsis of the 

 evolution of the foot and skull of the horse and the geological age in which 

 each stage is found. Across the alcove the visitor will find skeletons 

 of Eohippus, the four-toed stage of the horse and the earliest form that 

 has been discovered. These are specimens from the Wasatch and Wind 

 River beds of Wyoming and may have lived 3,000,000 years ago. It is 

 interesting to note that while there were no horses found in this country 

 by the white settlers, America is the original home of the horse. 



Passing from skeleton to skeleton the changes that have taken place 

 in the development of the horse are easily distinguished. The exhibit 

 is made more lifelike by plaster restorations of the animals and by water- 

 color sketches showing primitive horses in their environment. These 

 paintings and models are by Charles R. Knight. In the latter types of 

 the three-toed stage the two lateral toes have lost their original function 



