A Caltech Library Service

Rodents and Lagomorphs of the Upper Sespe

Wilson, Robert W. (1949) Rodents and Lagomorphs of the Upper Sespe. In: Some Tertiary Mammals and Birds from North America. Carnegie Institution of Washington Publication. No.584. Carnegie Institution of Washington , Washington, DC, pp. 51-65.

[img] PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


In contrast with the rodent faunules of the middle Sespe, that of the upper Sespe is represented by exceedingly few and fragmentary specimens. Even this scant assembly, however, indicates clearly, as do the larger mammals, that a much younger stage in geological time is recorded, namely early Miocene, possibly in part late Oligocene, rather than late Eocene. Some of the species were reported in an earlier paper (Wilson, 1934). In the present paper, all known specimens are discussed, and the stratigraphic value of the material is indicated. Although only 9 rodent and lagomorph specimens are known from the upper Sespe, these represent apparently 6 families. Seven rodent specimens are available, which fall into 5 families. Further, of the 7 known families from the Arikareean, including the John Day, 4 are recorded from the upper Sespe. Those absent are the Castoridae, Aplodontidae, and Mylagaulidae. The absence of the Aplodontidae may possibly be accounted for on the basis of geographic distribution. A member of the lschyromyidae is also present in the Sespe. Representatives of this family are common in older deposits, but so far they have remained unrecorded from the Arikareean stage.

Item Type:Book Section
Additional Information:© 1949 Carnegie Institution of Washington. The present paper was prepared during the author's tenure, 1946-1947, as a National Research Council Fellow in paleontology. The illustrations are the work of Mr. David P. Willoughby, staff artist in vertebrate paleontology, Division of the Geological Sciences, California Institute of Technology. The illustrations have been carefully prepared by the Division artist, Mr. David P. Willoughby.
Funding AgencyGrant Number
National Research CouncilUNSPECIFIED
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Balch Graduate School of the Geological Sciences406
Series Name:Carnegie Institution of Washington Publication
Issue or Number:584
Record Number:CaltechAUTHORS:20211217-234632115
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:112551
Deposited By: Tony Diaz
Deposited On:17 Dec 2021 23:57
Last Modified:17 Dec 2021 23:57

Repository Staff Only: item control page