Male Cyclommatus metallifer stag beetles use their long jaws, called mandibles, in scuffles for rotten wood and mating rights (as seen in the above video).
Once early humans didn't have to spend so much of their lives chewing, big teeth and long jaws stopped providing an advantage and natural selection could start favoring other traits instead.
Scientists wondered why beetles touting larger mandibles win more fights even though their long jaws should transmit less force to the pinching point, significantly reducing the strength of their grip.
The maned wolf has much longer legs than the Falklands wolf and long jaws suited for catching rats and mice; the island wolf has shorter, Labrador retriever-like jaws designed for grabbing and shaking large prey, such as seals and penguins.
Its long jaws contained, both sides combined, 58 or more banana-shaped teeth; larger tyrannosaurids possessed fewer teeth, Gorgosaurus at least sixty-two.
The very long jaws are positioned terminally (at the end of the snout), as opposed to the underslung jaws of most sharks.
