that mammoth was rare in the diets of the other Beringian carnivores. A stable isotope analysis of a mummified Beringian wolf pup dated 56,000 YBP that was recovered near the Klondike river revealed that most of its diet - and therefore its mother's diet - was based on aquatic rather than animal resources. The aquatic resources was proposed to be salmon. Dentition A 2007 study of Canis dentition shows that in comparison with the modern gray wolf and the Pleistocene LaBrea wolf, the Beringian wolf possessed large carnassial teeth and a short, broad palate relative to the size of its skull. The row length of the Beringian wolf's premolars was longer, the P4 premolar (the upper carnassial) longer and wider, and the M1, M2, and m1 (the lower carnassial) molars longer than those found in the other two types of wolves. The Beringian wolf's short, broad rostrum increased the force of a bite made with the canine teeth while strengthening the skull against the stresses caused by struggling prey. Today, the relatively deep jaws similar to those of the Beringian wolf can be found in the bone-cracking spotted hyena and in those canids that are adapted for taking large prey. Beringian wolves possessed a craniodental morphology that was more specialized than modern gray wolves and Rancho LaBrea wolves for capturing, dismembering, and consuming the bones of very large megaherbivores, having evolved this way due to the presence of megafauna. Their stronger jaws and teeth indicate a hypercarnivorous lifestyle. An accepted sign of domestication is the presence of tooth crowding, in which the orientation and alignment of the teeth are described as touching, overlapping or being rotated. However, a 2017 study found that 18% of Beringian wolf specimens exhibit tooth crowding compared with 9% for modern wolves and 5% for domestic dogs. These specimens predate the arrival of humans and therefore there is no possibility of cross-breeding with dogs. The study indicates that tooth crowding can be a natural occurrence in some wolf ecomorphs and cannot be used to differentiate ancient wolves from early dogs. Tooth breakage Tooth breakage is related to a carnivore's behavior. The mandibles of canids are buttressed behind the carnassial teeth to enable them to crack bones with their post-carnassial teeth (molars M2 and M3). A study found that the modern gray wolf possesses greater buttressing when compared to all other extant canids and the extinct dire