A Pliomastodon skull from the Thousand Creek beds, northwestern Nevada

Mastodon remains are not uncommon in the Thousand Creek Pliocene beds of northwestern Nevada but the materials found thus far represent fragmentary and isolated specimens. Merriam recorded the available specimens in 1911, including an incomplete skull which, unfortunately, was also poorly preserved. Because of lack of better material, determination of the mastodons has been unsatisfactory. Further collecting in these deposits in recent years by a field party of the California Institute of Technology yielded an incomplete skull. This specimen, found by Charles L. Gazin, furnishes an adequate basis for determining the relationships of the mastodon type occurring in the Thousand Creek fauna.