Vertebrate Zoology in the CU Museum of Natural History is a biodiversity repository of more than 120,000 specimens from five taxa: Fishes, Amphibians and Reptiles (Herpetology), Birds, and Mammals.Since our specimens document changes in biodiversity over the last 200 years, they are treasures of biological and historical significance. The Herpetology collection spans 77 countries, with its geographic strength in Mexican and the southwestern United States species. It contains over 68,000 specimens, including over 22,000 from Mexico, which have been actively studied and cited in systematic herpetology publications over recent decades. Additionally, the whiptail lizards (genus Aspidoscelis) are particularly well represented, including over 12,000 fluid-preserved specimens and two hundred dry skulls. The world-renowned herpetologists, Hobart M. Smith and T. Paul Maslin, as well as a number of their students and collaborators, were the major architects of our largest vertebrate collection. R. Earl Olson's contribution of 3,800+ specimens recently expanded our taxonomic and geographic coverage, including new material from Minnesota and Haiti. Most recently, Julio A. Lemos-Espinal contributed 2,600 specimens from the northern Mexican states of Sonora, Chihuahua, and Coahuila.