Contributors discuss George Gaylord Simpson and the history of paleomammalogy, anatomical evidence for superordinal/ordinal eutherian taxa in the cretaceous, molecular evidence for major placental clades, insectivoran-grade placentals, and characteristics of macroscelidea & tubulidentata,
paenungulata, xenarthra & pholidota, euarchonta, glires, chiroptera, carnivora, perissodactyla, artiodactyla, and cetacea.