Oct 1, 2014

Separated at Birth? Sabertooth Cat and a Can Opener

Sabertooth cats were not only built like living can openers, but they also functioned like them, according to a new study.

The paper, published in PLOS ONE, explains how now-extinct sabertooth cats likely killed their prey. The process, as it turns out, mirrored how can openers work -- specifically, the type of can opener with a long lever handle and a pointed triangular tip. You probably have such a device in a kitchen drawer.

The new research negates a prior theory about how sabertooth cats, which went extinct about 10,000 years ago, bit into prey. The discovery could even lead to a name change for the prehistoric ferocious felines.

Prior studies likened the cat's impressive canine teeth to knives, hence the word "saber." The theory held that the canine teeth were used to stab or slash the prey. Leaping onto its victim, the cat would plunge its upper canines into the prey, either eviscerating the animal or causing massive blood loss.

Other scientists, however, questioned whether the upper canines would have enough force to penetrate the hide of the prey without an opposing force from the lower jaw. This led to a widely accepted model called "the canine shear-bite." In this scenario, the cat used both its upper and lower jaws to bite the prey, but employed a downward nodding motion of its head to power the bite.

The new research counters this popular view. Geometric analysis, based on available sabertooth cat skeletons, determined that a downward motion of the cat's head would not increase the force of its bite. Given the cat's massively enlarged upper canines, how could it even produce enough force to close its jaws?

This is where the can opener mechanism comes in. The author of the new paper, Jeffrey Brown, calls it "the Class 1 Lever Model."

Brown, an independent researcher, believes that instead of the jaw muscles contracting to close the jaws, the cat may have immobilized its lower jaw against the neck of the prey, like the lug of a can-opener. Then, pushing with its forelimbs against the ground, the cat could elevate the base of its neck, rotating its head and canine teeth forward into the prey.

The mechanism is similar to the way in which an upward force against the arm of a can opener rotates the tip into a can.

Brown explained, "In the canine shear-bite, the cat's forelimbs restrain the prey and the neck powers the bite. In the Class 1 Lever Model there is an alternative method for restraining the prey, freeing the forelimbs to power the bite."

Read more at Discovery News

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