BYJAMES S. FINDLEY
University of Kansas Publications
Museum of Natural History
Volume 5, No. 36, pp. 633-639
December 1, 1953
University of Kansas
LAWRENCE
1953
University of Kansas Publications, Museum of Natural History
Editors: E. Raymond Hall, Chairman, A. Byron Leonard,
Robert W. Wilson
Volume 5, No. 36, pp. 633-639
December 1, 1953
University of Kansas
Lawrence, Kansas
PRINTED BY
FERD VOILAND, JR., STATE PRINTER
TOPEKA, KANSAS
1953
25-265
By
JAMES S. FINDLEY
Bones of a large number of vertebrates of Pleistocene age havebeen removed from San Josecito Cave near Aramberri, NuevoLeón, México. These bones have been reported upon in part byStock (1942) and Cushing (1945). A part of this material, on loanto the University of Kansas from the California Institute of Technology,contains 26 rami and one rostrum of soricid insectivores.Nothing seems to be known of the Pleistocene Soricidae of México.The workers cited do not mention them and no shrews are listedby Maldonado-Koerdell (1948) in his catalog of the Quaternarymammals of México. Comparison of these specimens with pertinentRecent material from México, the United States, and Canadaleads me to the conclusion that they represent two genera and atleast three species. The material examined is described below.
One right ramus, bearing all three molars but lacking the otherteeth and the tip of the coronoid process, needs close comparisononly with certain of the smaller North American species of Sorex.From S. merriami of southeastern Wyoming, it differs in having ashorter, much shallower dentary, a shorter molar row, and a lowercoronoid. In every particular it is identical with Sorex cinereus.Sorex cinereus from northern British Columbia and the specimenfrom Nuevo León differ from Sorex saussurei, S. obscurus, andS. vagrans in the ratio of the height of the coronoid to the lengthof the dentary. This ratio averages 49.6% in S. cinereus and 53.0%or more (up to 60.0%) in the other species. Microsorex hoyi differsfrom S. cinereus and from the specimen in question in deeper andshorter dentary, more robust condyle, dentary less bowed dorsally,molars shorter in anteroposterior diameter and higher in proportionto this dimension.
This record, as far as I can determine, constitutes a southwardextension of the known Pleistocene or Recent range of this speciesof approximately 800 miles. The nearest known occurrence ofS. cinereus in Recent times is in the mountains of north-centralNew Mexico. The species now has an extensive range in boreal[Pg 636]North America and prefers mesic and hydric communities fromwhich it rarely wanders. I know of no instance of the occurrenceof the cinereous shrew in desert areas such as there are betweenmany of the mountain ranges of southern New Mexico, Coahuila,and Nuevo León. Therefore, unless the habitat preferences of thespecies have changed since Pleistocene times, this find constitutesadditional evidence that more humid conditions at one time prevailedin the regions mentioned.