|FOSSIL LAND TORTOISES FROM RANCH 111 FOSSIL AREA, GRAHAM COUNTY, ARIZONA, WITH COMMENTS ON TORTOISES FROM OTHER LATE BLANCAN (EARLY PLEISTOCENE) SITES IN NEW MEXICO AND ARIZONA (TESTUDINIDAE, TESTUDINES)|
This project is a collaboration between Richard Franz, Robert McCord (Mesa Museum, Mesa, AZ), and Gary S. Morgan (New Mexico Museum of Natural History and Science, Albuquerque, NM).
SUMMARY. Fossil tortoise faunas from the early Pleistocene of Arizona and New Mexico are poorly known. Recent collecting at Ranch 111 in the Safford Basin in Arizona and Pearson Mesa, La Union, and other sites in the Rio Grande Basin in western and eastern New Mexico have revealed Blancan faunas that consist of a triad of tortoise species, represented by a large Hesperotestudo, small Hesperotestudo, and large Gopherus. It is unknown whether each of these triads is composed of similar or different fossil species. This study will evaluate each of the tortoise fauna, comparing them to determine how many species occurred during this period, 2-3 million years ago. We also want to compare them with other late Blancan tortoise faunas in Kansas, Texas and Florida to determine the range of variation between and among species and understand the distribution of Blancan faunas in a continental context.