MAMMUTHUS EXILIS FROM THE CALIFORNIA CHANNEL ISLANDS: HEIGHT, MASS, AND GEOLOGIC AGE

It can be demonstrated that Mammuthus exilis was present, in its normal size range, for at least the temporal period of ca. 200,000 to 11,000 years ago. Columbian mammoths (Mammuthus columbi) were also present, in lesser numbers, during that time span. In 1990, Louise Roth calculated body mass of island mammoths using the humerus and femur of two M. exilis individuals. At that time she was limited to using only museum specimens, due to the policies of the land owners on Santa Rosa Island. In 1994, we excavated the most complete specimen of M. exilis yet recovered. Beginning that winter, a pedestrian survey, searching for mammoth remains, was initiated. The survey was controlled by GPS (Global Positioning System) data entry for locations. The survey was conducted through 2008, producing more than 380 localities for mammoth remains on the islands of San Miguel, Santa Rosa, and Santa Cruz. Using specimens collected during these surveys, plus the donation of materials collected by the ranch families, the Los Angeles County Museum, and the Orr collections housed at the Santa Barbara Museum of Natural History, new and expanded interpretations and inferences are provided. The temporal range of island mammoths' residency has been expanded, plus the maximum size of M. exilis is considerable less than reported in earlier literature.