Age, Sex, Captivity, and tooth crowding in North American canids

Tooth crowding has been widely used to identify archaeological domestic dog remains including some of the earliest domestic dogs, based on the assumption that crowding emerges from shortening of the snout linked to neotony. Though neotony may induce dental crowding, crowding has been reported in captive wolf populations, and some Pleistocene wolves had more crowded teeth than Holocene wolves. Using data on North American canids, we demonstrate that captive wolves and coyotes have more crowded teeth than their wild counterparts. Second, a very weak correlation exists between tooth crowding and age. Finally, both mid-Holocene coyotes and wolves have more crowded teeth than their modern counterparts. These data lead us to conclude that tooth crowding is impacted heavily by behavior and biomechanical stressors and may provide insight into canid behavior in the past.