Clarendonian Insectrivora from the Ricardo Formation, Kern County California

Abstract

Two new insectivores of middle Clarendonian age are described from the upper part of the Ricardo formation, Kern County, California. Both species seem closely related to living North American representatives of their respective subfamilies. A soricine shrew, ?Hesperosorex chasseae, is represented by jaw fragments showing the complete lower dentition. These remains closely resemble the jaws and lower dentition of the living and fossil species of Notiosorex suggesting an ancestor-descendant relationship. Also represented by lower jaw fragments is a scalopine mole, Scapanus shultzi, the earliest record of the genus. Scapamis shnlfci seems most closely related to the hypsobrachyodont living species, S. orarius and S. towsendii, but could conceivable be ancestral to the hypsodont S. latinianus and even Scalopus (via the Blancan Hesperosculops) as well. Domninoides Green, 1956 is shown to be a talpid and not a soricid. It may be more closely allied to Parascalops than to the advanced scalopines such as Scapamis.