Thanks to Luke for suggesting this week's topic: Smilodon, the saber-toothed cat, AKA the sabertooth tiger!

Further reading:

Did sabertooth tigers purr or roar?

The double-fanged adolescence of saber-toothed cats

We don't know for sure what Smilodon looked like, but it might have been something like this:

An artist's rendition of an adolescent Smilodon with doubled fangs [picture from second link above]:

Show transcript:

Welcome to Strange Animals Podcast. I’m your host, Kate Shaw.

This week we’re going to learn about an animal suggested by Luke, the sabertooth tiger, also called the sabertooth cat since it wasn’t actually a tiger, also called smilodon after its scientific name. We’ve talked about it before, way back in episode 34, but a lot of new studies have been published since then and we know a lot more about this terrifying-looking animal!

The genus of the saber-toothed cat is Smilodon, so that’s mostly what I’m going to call it in this episode. It’s classified as a member of the family Felidae, which is the same family where you find domestic cats, wildcats, big cats, and lots of extinct animals like the cave lion, but Smilodon wasn’t closely related to what we think of as cats. There were at least three species of saber-tooth cats in the genus Smilodon that we know of, but it had many other similar-looking relatives.

Smilodon is best known from the La Brea tar pits in Los Angeles, California, where the remains of hundreds of individuals have been discovered. That’s a big reason why we know so much about Smilodon, especially the species Smilodon fatalis that lived in North America and parts of South America. An even bigger species lived exclusively in South America, while both were probably descended from a smaller species that also lived in South America.

S. fatalis is estimated to have grown up to 39 inches tall at the shoulder, or 99 cm, while S. populator stood at an estimated 47 inches tall, or 119 cm. That’s almost four feet tall. Some full-grown humans are that height! Smilodon was so stocky and heavily muscled that it probably looked more like a bear than a cat. Its had a broad head and jaws that could open much wider than most modern animals, which allowed it to deploy its most deadly weapon, its saber teeth, without its jaw getting in the way.

Smilodon’s saber teeth were as much as 11 inches long, or 28 cm, although S. fatalis typically had teeth around 8 inches long, or 20 cm. Big as they were, the saber teeth were also relatively delicate. A young Smilodon didn’t start growing its big teeth until it was about a year old, and even then it had to learn how to use them so they wouldn’t break. Luckily for adolescent smilodons, they didn’t lose their baby fangs until they were fully grown.

Most mammals only grow two sets of teeth in our lifetimes. The first set is usually called baby teeth or milk teeth. As the baby grows up, its adult teeth start growing in one at a time. The adult tooth pushes at the baby tooth until it gets loose and either comes out on its own or, in the case of me in second grade, I asked to go to the bathroom and then spent half an hour twisting at a loose baby tooth until it finally came out, along with some blood. But I got a quarter that night from the tooth fairy. (Kids, maybe don’t do that.)

In the case of a young smilodon’s saber teeth, they grew in just next to the baby fangs. Instead of pushing the baby fangs out, the new teeth grew alongside them and even had a groove for the baby teeth to fit into. When scientists first discovered preserved jaws with these double fangs, they thought it was a fluke, that sometimes the new teeth came in wrong and didn’t push the old teeth out. That happens in humans sometimes too and then you have to go to the dentist to get the old baby teeth taken out. But paleontologists kept finding these double toothed jaws, and only in adolescent smilodons.

Finally a team of scientists studied the teeth carefully and made...