Issue
Table of Contents

Taxonomic diversity of ochotonids:
ERVAJEVA ET AL.

Plain-Language &
Multilingual  Abstracts

Abstract

Introduction

Materials

The Diversity of Ochotonids and their Evolutionary Development

Review of North American Pikas of the Past

Comparison between Living Asian and North American Pikas

Conclusions

Acknowledgments

References

 

 

Print article

 

 
 

INTRODUCTION

The family Ochotonidae (Lagomorpha) includes 16 extinct genera and one extant genus (Ochotona). Studies indicate that the ochotonids show general evolutionary trends in the cheek teeth. These trends include a shift toward rootlessness and hypsodonty, increasing complexity in the enamel structure of the P3 and P3, increasing depth of the hypostria of P4-M2, and widening of the talonids of P4-M2 from narrow to wide (Erbajeva 1994).

Morphological examination of cranial and postcranial skeletons of both extinct and living taxa indicates that the main external features of ochotonids remained invariable for a long time (Gureev 1964; Polyakova and Erbajeva 1974; Erbajeva 1994). Current data suggest that the principal ochotonid adaptations developed in the Oligocene and have mostly been retained. Based on similar dental structures in fossil and modern pikas, it is likely that fossil forms had similar ecologic requirements (e.g., open landscapes, grass diet) (Gureev 1964; Erbajeva 1988; Mead and Spaulding 1995).

 

 

 

Next Section

Taxonomic diversity of ochotonids
Plain-Language & Multilingual  Abstracts | Abstract | Introduction | Materials
The Diversity of Ochotonids and their Evolutionary Development
Review of North American Pikas of the Past | Comparison between Living Asian and North American Pikas
Conclusions| Acknowledgments | References
Print article