Prehistoric Saber-Tooth Cats Grew Their Teeth Long and Fast

According to recent findings, the fierce teeth of the saber-toothed cat Smilodon fatalis grew long and sharp but not so early, with the permanent upper canines reaching full development at around 3 years. Paleontologists believe the techniques applied may be useful in understanding the growth rate and development of other extinct species.

Saber-toothed Fossil Analysis Shows Fast Growth, Long Development

The saber-toothed cat is known for its long, sharp canines that grew to be about 7 inches long (18 centimeters). However, a recent study shows that those fierce teeth only fully developed after three years, which is notably later than modern cats. However, what’s truly remarkable is that the saber-tooth’s teeth grew an estimated 6 millimeters a month. In comparison to modern cats, including African lions, this was a growth rate that was twice as fast.

Researchers used a novel technique that was a combination of isotopic analysis and x-ray imaging. With the new approach, they became the first to reveal the specific developmental ages of Smilodon with particular regard to the cat’s notable teeth.

The paper was published in the journal PLOS ONE co-authored by Z. Jack Tseng from the American Museum of Natural History’s Division of Paleontology and Robert Feranec of the New York State Museum.

The Science Behind Giving Saber-Tooth Development Ages

About 10,000 years ago, the saber-tooth cats of S. fatalis that lived in North and South America went extinct, though they live on in the general public’s memory for their massive teeth. However, little else was known about when exactly the animals grew such exaggerated chompers even though researchers had access to several well-preserved S. fatalis fossils.

Robert Feranec, co-author of the study pointed out the importance of understanding the growth of the saber-tooth’s trademark characteristic.

“Changes in the timing of life-history events can have major effects on an organism’s adult features and final appearance,” said Feranec, who is also New York State Museum’s curator of Pleistocene vertebrate paleontology.

In order to find out the timeline of the teeth, the researchers gathered specimens from the La Brea Tar Pits in Los Angeles. They then applied the new combination technique of stable oxygen isotope analyses and micro-computed tomography. With help from Clemson University and the Neural Stem Cell Institute, the researchers were able to calculate the specific eruption rate of the saber teeth.

Previous research on these cats only gave relative dates, but this special technique was able to accurately date the distinct developmental ages. The research can now be applied to other extinct species as well.

The importance of their saber teeth and Other Saber-tooth Cat Facts

When a prehistoric animal such as the saber-toothed cat lives in a rough age of predator versus prey, the time it takes for the cat to develop its teeth is quite important. As their main weapon against predators and one of their only tools to tear open prey, the saber-tooth’s teeth were vital.

Like other mammals, the saber-tooth cat had two sets of teeth similar to humans where the first set of “baby” teeth grow in and subsequently fall out to make room for the second set or permanent teeth. For the saber-tooth, the first set stopped erupting at about one-and-a-half years, when the cub was still a small creature. Then about 11 months after the first set stopped growing, the second set would squeeze in with the first set.

The researchers noted that even though the first set were not the permanent, more lethal teeth, the saber-toothed cubs had jaw muscles that were already fully developed, enabling them to hunt prey with what we would consider their baby teeth. After nearly 2 years, those baby teeth would fall out while the permanent ones continued growing for the next year to year-and-a-half.

During this time, the cubs would have been extremely vulnerable to the many predators that awaited a tasty cub sandwich. Researchers theorized that during the time it took for the full emergence of permanent teeth, the adults likely took care of the cubs by hunting for their food.

New techniques can help research other extinct animals’ development

With this recent, cutting-edge technique used to research the saber-tooth cats, other extinct animals now have a greater chance of having the secrets of their development revealed too.


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