The Sabertooths, Part 2: Saberteeth

Saberteeth are a cat’s upper fangs, flattened as well as lengthened. Modern cats don’t have them, even though they are hypercarnivores just like their extinct sabercat cousins.

Hypercarnivores need at least 70% of their diet to come from meat. This is why Fluffy the Housecat can’t live on dog food – it needs the special balance of protein and amino acids that canned and dry cat food contains.

In the wild, cats depend on prey animals. To survive, their canine teeth have evolved into fangs. (Holliday and Steppan; Kitchener and others)

Bengal tigers have the largest fangs of any modern cat – up to 4 inches (10 cm) long. (Heske, Lab 19)

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The fangs of this Brazilian jaguar along the Rio Negro are impressive, too.

In comparison, Smilodon’s saberteeth were almost a foot (28 cm) long! (van den Hoek Ostende and others)

But those weren’t really fangs.

In today’s big cats, fangs are rather cone-shaped – thick at the base and tapering up into a rounded point.

Saberteeth were much flatter, front to back, than the fangs of any “normal” modern cat. (Martin, 1980; van den Hoek Ostende and others)

The edges looked like knives. Indeed, the technical name for sabertoothed cats is Machairodontinae, which means “Knife-Tooths.” (Antón; Turner and others)

But appearances are deceptive. Saberteeth were actually blunter than a steel blade, although sometimes they were serrated. (Turner and Antón)

Mechanical experiments show that saberteeth could only cut through hide and animal tissues when the cat also made a slicing movement during its killing bite. (Wheeler)

Hence the name ambush-and-slash for a sabertoothed predator’s hunting style. In contrast, all modern cats use a stalk-and-pounce hunting technique. (Werdelin, 1989)

Paleontologists have found subtle differences in saberteeth between two major sabertoothed cat tribes, the Homotheriini and the Smilodontini.

Homotherium and its relatives were scimitar-toothed. Their saberteeth tended to be broad and very flat, with coarse serrations. (Antón; Martin, 1980)

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Homotherium

The Smilodontini were dirk-toothed cats. Their sabers were generally longer and straighter, less flattened, and with very fine serrations to none at all. (Antón; Martin, 1980)

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Smilodon populator was an extreme dirk-tooth. (Note: Per Antón, the species name “necator” isn’t used any more.)

These differences matter a lot to experts since they may provide some clues as to how each apex predator used its teeth and fit into those long-vanished ecosystems.

But for general purposes, it’s still perfectly okay to just call them all sabertooths.

But not all sabertooths were members of the cat family.

To be continued tomorrow


Images

Featured image: Hoplophoneus primaevus, by James St. John, Flickr. CC BY 2.0.

Yawning jaguar: Charles J. Sharp, Sharp Photography, Flickr. CC BY-SA 4.0.

Homotherium crenatidens, Muséum national d’Histoire naturelle, Paris: Ghedo. Public domain.

Smilodon upper skull: Cope, E. D. 1880. On the extinct cats of America. American Naturalist. xiv (12):833-857, figure 13.


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This series on sabertooths was originally posted at my Robin Huntingdon blog about a year ago.


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