UNIVERSITY OF CALIFORNIA PUBLICATIONS 



BULLETIN OF THE DEPARTMENT OF 



GEOLOGY 



Vol. 7, No. 21, pp. 397-418, 14 text figures Issued December 16, 1913 



PRELIMINARY REPORT ON THE HORSES 

 OF RANCHO LA BREA 



BY 



JOHN C. MEERIAM 



CONTENTS 



PAGE 



Introduction 397 



Skull 400 



Dentition 404 



Comparison with Equus caballns 412 



Relationship to Pleistocene species of Western North America 413 



Relation to Equus occidentalis Leidy 413 



Comparison with Equus pacificus Leidy 414 



Comparison with Equus excelsus Leidy 415 



Comparison with Equus scotti Gidley 416 



Comparison with Equus niobrarensis Hay 416 



Comparison with Equus laurentius Hay 418 



Summary - 418 



INTRODUCTION 



Remains of horses have heen obtained in considerable 

 numbers from the Pleistocene beds of Rancho La Brea, but not 

 until within the last year has skull material been found in such 

 quantity as to make possible a critical study in which the 

 important factors of individual and age variation could be con- 

 sidered with any degree of satisfaction. In the excavations 

 recently carried on through the kind permission of the late 

 Madam Plancock Ross, and her son, Mr. G. Allan Hancock, a 

 number of good skulls have been obtained, with much material 

 consisting of loose teeth and elements representing all parts of 



