Age determination of the Mongolian wild ass (Equus hemionus Pallas, 1775) by the dentition patterns and annual lines in the tooth cementum

Abstract

Based on 440 skulls recently collected from two areas of the wild ass population in Mongolia, the timecourse of tooth eruption and replacement was investigated. The dentition pattern allows identification ofage up to five years. We also conclude that annual lines in the tooth cementum can be used to determinethe age in years for wild asses older than five years after longitudinal tooth sections were made with a lowspeedprecision saw. The first upper incisor proved to be most suitable for age determination, although thestarting time of cement deposition is different between the labial and lingual sides of the tooth. The accurateage of the wild ass can be determined from the number of annual lines and the time before the first formationof the cementum at the respective side of the tooth.