A new analysis of the distinctive canines of the saber-toothed tiger (Smilodon fatalis) suggests that the baby tooth — one of the deciduous teeth all mammals grow and lose by adulthood — that preceded each saber stayed in place for years to stabilize the growing permanent saber tooth, perhaps allowing adolescents to learn how to hunt without breaking them.
This new study provides the first evidence that the saber tooth alone would have been increasingly vulnerable to lateral breakage during eruption, but that a baby or milk tooth alongside it would have made it much more stable.
The evidence consists of computer modeling of saber-tooth strength and stiffness against sideways bending, and actual testing and breaking of plastic models of saber teeth.
“This new study is a confirmation — a physical and simulation test — of an idea some collaborators and I published a couple of years ago: that the timing of the eruption of the sabers has been tweaked to allow a double-fang stage,” said study author Dr. Jack Tseng, a plaeontologist at the University of California, Berkeley.
“Imagine a timeline where you have the milk canine coming out, and when they finish erupting, the permanent canine comes out and overtakes the milk canine, eventually pushing it out.”
“What if this milk tooth, for the 30 or so months that it was inside the mouth right next to this permanent tooth, was a mechanical buttress?”
“The unusual presence of the baby canine long after the permanent saber tooth erupted protected the saber while the maturing tigers learned how to hunt without damaging them.”
“Eventually, the baby tooth would fall out and the adult would lose the saber support, presumably having learned how to be careful with its saber.”
Paleontologists still do not know how saber-toothed animals like Smilodon hunted prey without breaking their unwieldy sabers.
“The double-fang stage is probably worth a rethinking now that I’ve shown there’s this potential…
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