Extinct Teratorn (Family Teratornithidae) 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.

• Teratorns were predatory carnivores (Campbell & Tonni 1981) and possibly opportunistic scavengers (Hertel 1995)
• Probably hunted in daytime, using thermals for flight. (Chatterjee et al 2007)
• Possible killing techniques suggested by one researcher include flicking prey sharply to the ground.(Campbell & Tonni 1981).
• The beak of T. merriami was not strong enough to kill by biting. (Campbell & Tonni 1981).
• The huge teratorn Argentavis could kill sizeable prey with its large beak.(Chatterjee et al 2007)
• A study by Hertel (1995) suggested teratorns were fish-eaters, specializing in plucking fish from the surface of water with their beaks, although Campbell (1981) says they weren't agile enough to capture aquatic prey on the wing.
• Argentavis magnificens could have swallowed hare-sized prey in one gulp. (Campbell & Tonni 1983)
  • Estimated to have eaten 5-10 kg of meat daily (Palmqvist & Vizcaíno 2003)
  • Armadillos, rodent-like mammals, possums, and capybara may have been food for this large teratorn.
  • Both Argentavis and Teratornis merriami had similar feeding mechanisms (Campbell 1981)
• T. merriami prey hypothesized to be lizards, snakes, small and medium-sized mammals, birds. (Campbell & Tonni 1983)
  • T. merriami grasped prey with hooked bill
  • Very mobile (kinetic) skull bones helped teratorns hold and swallow struggling prey without damage to themselves.

Campbell & Tonni (1981,1983)
Chatterjee et al. (2007)
Hertel (1995)
Palmqvist & Vizcaíno (2003)