Extinct Dire Wolf (Canus dirus) Fact Sheet: Diet & Feeding

Clues to fossil mammals' diets come from teeth, skull shape and the positions and strength of major jaw muscles, from fossilized dung and guts, from oxygen isotopes in bone and teeth, and from diets of similar modern animals.

• Often took large prey, as inferred from:
  • Large body size
  • Carnivorous, meat-eating dentition
• Were not specialized predators, fed on whatever megafauna were most abundant. (Fox-Dobbs et al 2007)
  • Horses were important prey; sloth, mastodon, bison and camel were less common prey.
• Fed on medium to large hooved animals. (Hodnett et al 2009)
  • Ate both ruminants and non-ruminants (Coltrain et al 2004)
  • Maximum prey size would have been 300-599 kg (Anyonge & Roman 2006) (Van Valkenburgh & Hertel 1998)
  • A pack of dire wolves could even have preyed on adult bison. (Anyonge & Roman 2006)
• May have also supplemented diet with smaller prey species (Fox-Dobbs et al 2003)

• Calculated bite force: (Therrien 2005)
  • 129% of modern gray wolves
  • 64% of the extinct American lion
• Some researchers suggest that, like many canids, probably hunted in packs, normally subdued prey with many shallow, debilitating bites (Ewer 1973) (Therrien 2005)
• Other researchers note that teeth and jaws may also have held struggling prey (Van Valkenburgh & Ruff 1987)
  • Dire wolves had great degree of roundness and greater bending strength in canine teeth, when compared with modern wolves (prey must have not been subdued immediately).
  • Smilodon, by contrast had more delicate teeth that probably didn't come in contact with the prey's bones (used powerful front limbs to subdue prey)
• Studies of twisting and stress forces generated at different points of carnivore jaws reveal: (Therrien 2005)
  • Like other canids, dire wolves' lower jaws fortified behind the slicing carnassial molars (for bone-crushing),
  • Dire wolves could crush bones, but not as well as modern wolves
  • When dire wolves compared to large cats, bite force not as strong in the front of the jaw (where cats use the canine for a killing bite)
• Extinct dire wolves, saber-tooth cats, and American lions all competed for similar prey. (Coltrain et al 2004)
  • According to nitrogen isotope values of bone
  • Large numbers of broken teeth suggest high levels of competition for carcasses. (Van Valkenburgh 1998)
• May also have scavenged large portions of prey that Smilodon didn't finish.

Anyonge & Roman (2006)
Coltrain et al. (2004)
Ewer (1973)
Fox-Dobbs et al. (2003)
Fox-Dobbs et al. (2007)
Harris et al. (2004)
Hodnett et al. (2009)
Therrien (2005)
Van Valkenburgh & Ruff (1987)
Van Valkenburgh (1998)
Van Valkenburgh & Sacco (2002)