The ruminants are a diverse and important group of mammals, comprising 35 genera in nine families, including bovids (goats, sheep, cows), cervids (deer, elk) and giraffids. These and several extinct groups of ruminants are represented in the fossil record, but the detailed morphology of their cranial bones has not been studied in detail. To date, most comparative research on the classification and evolution of fossil and living ruminants has been based on post-cranial skeletal remains (especially features of the limbs) and teeth. Dr. S. David Webb proposes an ambitious study of cranial morphology of representatives of living and fossil ruminant groups, for the purpose of reconstructing their evolutionary relationships. The results of his analysis will be compared and integrated with results based on non-cranial data, and several varieties of molecular data, including mitochondrial DNA sequences. The proposed research has wide implications. A synthesis of new and existing data will help to crystallize the most precise picture of ruminant evolution to date. A robust family tree for adaptation, biogeography, functional morphology, and biodiversity. The results of this research will find a wide audience among comparative anatomists, mammalogists, and evolutionary biologists.