Breakage rates for grey wolves and coyotes are 4% and 5% respectively today; in the Pleistocene they were 10% and 7%.

• 化石中的牙齿和现代动物的牙齿差异巨大：现代灰狼和土狼的牙齿断裂频率分别是4%25和5%25，在更新世分别是10%25和7%25。