Genera and Subgenera of Chipmunks   By: John A. White

University of Kansas Publications Museum of Natural History

Volume 5, No. 32, pp. 543 561, 12 figures in text

December 1, 1953

University of Kansas LAWRENCE 1953

UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY

Editors: E. Raymond Hall, Chairman, A. Byron Leonard, and Robert W. Wilson

Volume 5, No. 32, pp. 543 561, 12 figures in text

December 1, 1953

UNIVERSITY OF KANSAS Lawrence, Kansas

PRINTED BY FERD VOILAND, JR., STATE PRINTER TOPEKA, KANSAS 1953

Genera and Subgenera of Chipmunks By JOHN A. WHITE

CONTENTS

PAGE Introduction 546 Historical 546 Methods, Materials, and Acknowledgments 547 Evaluation of Characters 548 Characters in which the Subgenera Eutamias and Neotamias Agree, but Differ from the Genus Tamias 548 Structure of the Malleus 548 Structure of the Baculum 549 Structure of the Hyoid Apparatus 552 Presence or Absence of P3 553 Length of Tail in Relation to Total Length 553 Color Pattern 554 Characters in which the Subgenus Eutamias and the Genus Tamias Agree, but Differ from the Subgenus Neotamias 554 Shape of the Infraorbital Foramen 554 Width of the Postorbital Process at Base 554 Position of the Supraorbital Notch 554 Degree of Convergence of the Upper Tooth rows 554 Degree of Constriction of the Interorbital Region 555 Shape of the Pinna 555 Structural Features that are too Weakly Expressed to be of Taxonomic Use 555 Discussion 555 Genera and Subgenera 557 Genus Eutamias Trouessart 557 Subgenus Eutamias Trouessart 558 Subgenus Neotamias Howell 558 Genus Tamias Illiger 559 Discussion 559 Conclusions 560 Literature Cited 561

ILLUSTRATIONS

Figs. 1 3. Dorsomedial Views of Malleus 549 Figs. 4 10. Lateral Views of Baculum 551 Figs. 11 12. Ventral Views of Hyoid Apparatus 552

INTRODUCTION

The supraspecific categories of the chipmunks, as in most other groups of squirrels, have been a source of controversy for many years. Before presenting new evidence and a review of older evidence bearing on the problem, it seems desirable to review briefly in chronological order, the taxonomic history of the genera and subgenera of the chipmunks.

HISTORICAL

Linnaeus (1758:64) described the eastern North American chipmunks under the name Sciurus striatus and based his description on that of Catesby (1743:75). The Asiatic chipmunk was first described, under the name Sciurus sibiricus , by Laxmann (1769:69). Schreber (1785, 4:790) separated the Asiatic and North American chipmunks into the Asiatic and American varieties. Gmelin (1788:50) followed Schreber and, employing trinomials, used the names Sciurus striatus asiaticus and S. s. americanus . Illiger (1811:83) proposed Tamias as the generic name of the chipmunk of eastern North America. Say (1823:45) described Sciurus quadrivittatus , the first species of chipmunk known from western North America.

Trouessart (1880:86 87) proposed Eutamias as the subgeneric name to include the western North American and Asiatic chipmunks.