Double Trouble: The Fantastic Secret of Teenage Saber-Toothed Cats | Science news
New evidence indicates that saber-toothed cats held baby paws to stabilize the growing sabers. Adolescent saber-toothed cats would have twin pairs of canines. The research is based on mechanical analysis.
An illustration of teenage saber-toothed cats. (Image credit: Massimo Molinero).
New Delhi: A mechanical analysis of the distinctive canines of Smilodon fatalis, the California saber-toothed cat, revealed that the baby tooth that preceded each saber remained in position for years to stabilize the growth of the permanent sabers, potentially allowing adolescents to learn to hunt without breaking the huge canines. More than 2,000 saber-toothed skulls have been excavated from the La Brea Tar Pits near Los Angeles, although few have sabers attached.
A fully grown baby tooth with its saber erupting. (Image credit: Jack Tseng, UC Berkeley).
Some though exhibited a peculiar feature: the saber tooth socket was occupied by not one but a pair of teeth, with the permanent tooth fitted into a groove within the baby tooth. Paleontologists don’t think these double tusks were a genetic fluke. Nine years ago, a team of scientists speculated that baby teeth helped stabilize permanent sabers against lateral breakage as they erupted and grew.
Based on growth data, scientists were able to determine that the twin teeth existed side by side for up to 30 months during the animal’s adolescence, after which the baby teeth were lost. Now, in new research, researchers have used mechanical analysis to determine that the saber tooth itself would have been increasingly vulnerable to lateral damage during the growth phase, with baby teeth making growth much more stable. In fact, researchers tested breaking plastic models of saber teeth.
Time is of the essence
An article describing the research was selected for publication in The Anatomical Record. Paper author Jack Tseng says: “This new study is a confirmation – a physical and simulation test – of an idea that some collaborators and I published a few years ago: that the timing of the saber eruption was adjusted to allow for a double prey stage. 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 baby tooth, during the approximately 30 months that it was inside the mouth, right next to this permanent tooth, was a mechanical support?”
