The extinction of the dinosaurs 66 million years ago kicked off the age of mammals.
Soon enough, several giant herbivorous mammals such as ground sloths, giant bison, horses, and mammoths emerged from smaller critter-like ancestors.
As the herbivores grew bigger, several carnivores also emerged to take advantage of the abundance of prey.
Some of them developed impressive adaptations to increase their efficiency as predators.
One such adaptation is the development of long, fang-like teeth effective for stabbing and killing prey.
Cat-like animals with this type of adaptation were collectively called saber-tooths or saber-toothed cats.
An elongated canine teeth is one of the most common adaptations in carnivorous animals today, but the saber-toothed cats took theirs to a different level.
Some of them had upper canines that were up to 20 centimeters (8 inches) long.
Various groups of unrelated carnivorous mammals developed a long and curved saber-shaped canine just like this over the course of geologic history.
The oldest evolved during the Permian Period, over 200 million years ago.
Over time, several other carnivorous mammals with similar adaptations emerged and disappeared.
The Smilodon, or saber-toothed cat, is one of the best-known saber-tooths to have ever lived.
This distant relative of modern cats lived in the Americas during the Pleistocene Epoch, starting about 2.5 million years ago.
The Smilodon represents the peak of sabertooth evolution in mammalian carnivores, and they flourished for several million years as the planet’s top predator.
Things changed during the last ice age, and by 10,000 years ago, the Smilodon became extinct.
The extinction of the saber-toothed cats is closely linked to the disappearance of other large mammals in the Americas during the Pleistocene Epoch.
Understanding why the Smilodon went extinct can provide a clue to understanding the disappearance of the Earth’s megafauna around the same period.
In this article, we explore the sabertooth tiger extinction to understand when, how, and why one of Earth’s prolific predators suddenly went extinct.
Sabertooth Tiger Extinction Timeline
Although the Smilodon was the last saber-toothed cat, carnivores have developed a saber-like dentition at least seven times in the fossil record, dating as far back as the Permian Period.
Many of the ancient species to demonstrate this adaptation were not even cats at all.
For instance, the first saber-toothed carnivore ever recorded in the fossil record was a group of reptile-like mammals known as the gorgonopsids.
A notable member of this group was the Smilesaurus.
The gorgonopsians all went extinct at the end of the Permian Period.
The next wave of saber-tooths were the metatherians.
These were marsupial mammals that lived during the Cretaceous Period.
The Deltatheroida lineage came first during the Cretaceous and was succeeded by sparassodonts like the Thylacosmilus during the Miocene Epoch.
The feliform saber-toothed predators emerged during the Middle Eocene Epoch (about 40 million years ago), represented by the nimravids.
They are commonly called the “false saber-toothed cats” because they were not actual cats (felids), even though they were cat-like.
The same applies to the barbourofelids, a different group of feliform mammals that emerged during the Miocene and went extinct about nine million years ago.
The true saber-toothed cats were the machairodonts.
These felids emerged about 16 million years ago and thrived throughout the Miocene to the Pleistocene epochs.
This group includes the more familiar Smilodon, along with others like the Homotherium and Meganteron.
The true saber-toothed cats roamed the landscape of Europe and North America during the Miocene and Pliocene epochs.
The Smilodon, the most popular member of this group, emerged during the Pleistocene Epoch about 2.5 million years ago.
They were present in both North and South America during this period.
The Smilodon is one of the last of the saber-toothed cats, and it disappeared about 10,000 years ago.
The extinction of the Smilodon coincides with the end of the last ice age.
The glacial period ended with an extinction event known as the Quaternary extinction event.
This 1500-year period saw the end of at least 15 different species of mammals in the Americas.
Causes of Sabertooth Tiger Extinction
Although we have a reasonably good idea of when the sabertooth tiger went extinct, the how and why of their extinction isn’t entirely clear.
Various environmental and ecological factors have been put forward to explain the extinction of this unique family of cats.
Throughout geologic history, climate change has always been one of the significant factors driving extinction events.
This was the case with the Quaternary extinction event, too.
As the ice age ended, climatic fluctuations altered Earth’s weather and vegetation patterns.
Glaciers began to recede across the continents.
The sea level rose, precipitation patterns changed, and global temperatures rose by up to six degrees.
Within a short period, the Pleistocene grasslands were transformed into forests.
The climatic changes had a two-pronged effect on the sabertooth.
First, they faced habitat loss just like other animals alive at the time.
Saber-toothed cats were probably well adapted to the cold, dry conditions of the ice age.
When the climate suddenly started to warm up, they would have struggled to survive in the warmer, wetter conditions that followed.
The second effect was the scarcity of the Smilodon’s typical prey animals.
Scientists think the rapid change in climatic conditions drove larger animals like the bison and mammoths that were adapted to the glacial environment into extinction.
The disappearance of this prey species would have caused a cascading effect throughout the late Pleistocene ecosystem, culminating in the disappearance of predator species like saber-toothed cats.
Mechanisms Behind Sabertooth Tiger Extinction
In the past, it was assumed that the disappearance of the sabertooth tiger was a straightforward case of a species lost to climate change.
But a closer look suggests that the mechanism of their extinction was probably more complex than initially imagined.
First, the Pleistocene Epoch was characterized by numerous glacial and interglacial periods.
This means the ice age that occurred at the end of the period was not the first one the saber-toothed cats had to endure and survive.
It suggests that there were most likely unique conditions during the quaternary extinctions that were absent during previous interglacial periods.
Narrow Specialization
Sabertooth tigers primarily hunted large herbivores such as mammoths, bison, and ground sloths.
Their extinction at the end of the Pleistocene wasn’t caused by the disappearance of these prey species but by their inability to the composition of the fauna due to narrow specialization.
The large herbivores they typically preyed on were replaced by smaller and more agile herbivores like deer and antelopes.
Narrow specialization can be an advantage in a balanced ecosystem.
As narrowly specialized predators of large animals, Saber-toothed cats developed long, sharp canines that were well-suited for piercing the tough flesh of their typical prey.
This would also give them a comparative advantage against predators with a more generalized diet.
But hunting sluggish animals meant the saber-tooths were not very good at running or climbing.
When their giant lumbering prey disappeared and were replaced by more agile and smaller animals, the Smilodon would have had difficulty adjusting.
Competition With Humans
Another element that was absent during previous ice ages but present during the last ice age was the presence of humans in the Americas.
During the Late Pleistocene Epoch, humans migrated from the Old World to North and South America.
The arrival of these early humans between 12,000 and 10,000 years ago coincides with the disappearance of many of the continent’s megafauna.
Humans hunted many large Pleistocene megafauna (including some of the usual prey of the sabertooth tigers) for food and other resources.
Overhunting by humans and habitat loss due to the activities of early humans contributed to the rapid disappearance of many animal species during the Quaternary extinction event.
Low Genetic Diversity
Low genetic diversity is another factor that may have contributed to the global decline of the sabertooth tigers.
As glaciers melted and the Pleistocene landscape changed, sabertooth tiger populations were broken into smaller groups of closely related individuals.
A lack of genetic diversity may lead to inbreeding, which makes a species susceptible to diseases and genetic deformities that put them at a disadvantage, especially during harsh periods of changing environmental conditions.
Controversies About the Mechanisms of Sabertooth Tiger Extinction
Generally, most experts agree that the Smilodon’s narrow specialization on large prey may have contributed to their decline.
However, a study of the Smilodon’s tooth wear pattern, published in 2012, found no evidence that the predator faced severe food scarcity towards the end of the Pleistocene.
Generally, if a lack of suitable food sources drove the Smilodons to extinction, one would expect their foraging behavior to change significantly.
For predators like saber-toothed cats, a lack of food would mean scavenging more on carcasses and even eating bones.
Yet, the study found no significant changes in the wear patterns of their teeth, meaning their diet was consistent throughout time, even towards the end of their existence.
This discovery that the sabertooth had enough to eat towards the end of their existence also casts some doubts on the role the early humans allegedly played in the extinction of the sabertooth tigers.
Similarly, some experts have theorized that saber-toothed cats were displaced by faster and more generalized felids more similar to modern cats.
Those who agree with this theory think the extremely long sabertooth of this predator would have given them a weaker bite.
In addition, the saber-toothed cats were also less agile compared to these new predators, which would make them inferior hunters.
One problem with this theory is that other carnivores more similar in form to modern felids, such as the American lion, also went extinct during the Quaternary extinction.
This suggests that other factors aside from the morphological limitations of the Smilodon contributed to their disappearance.
Smilodon Extinction Status and Comparison
As earlier explained, the Smilodon is not the only saber-toothed cat to have ever evolved.
Several other unrelated but similar-looking predators evolved at various points in geologic history.
Some of them include the nimravids, barbourofelids, and thylacosmilids.
These saber-toothed predators evolved and died off several million years before the more familiar saber-tooths evolved.
Smilodon and Homotherium are the last surviving saber-toothed cats to walk the planet.
These big cats were about the same size as modern lions but with a more robust build and longer, dagger-like canines.
Homotherium went extinct about 12,000 years ago, while the Smilodon died off about 10,000- years ago.
The Smilodon is sometimes referred to as the saber-toothed tiger.
However, it is worth noting that they’re not directly related to living tigers (Panthera tigris).
They’re felids, which means they belong to the broad group of carnivores collectively referred to as cats.
This does not mean they’re the direct ancestor of modern tigers or evolved into tigers.
Tigers evolved from the same common ancestors as modern lions, leopards, and jaguars about 2.8 million years ago and are still alive in parts of Asia today.
Status of the Sabertooth Tiger: Extinct or Not?
Smilodon and all members of the saber-toothed cat family are indeed extinct.
These prehistoric mammals lived during the Pleistocene Epoch, between 2.5 million years ago and approximately 10,000 years ago.
There are no living sabertooth tigers or any species closely related to them.
Although the term “sabertooth tiger” is often used to refer to the Smilodon and other similar-looking extinct animals, the saber-toothed cats are not true tigers.
In fact, many of them are not even cats at all.
Only the Smilodon and its close relatives within the Machairodontinae family can be accurately described as cats since they belong to the Felidae family.
Current Conservation Efforts and Future Prospects
Since the saber-toothed cats went extinct about 10,000 years ago, protecting or conserving them isn’t possible.
However, the Smilodon and other Pleistocene megafauna are often mentioned in conversations about extinction and efforts to conserve extant species at the brink of extinction.
This is due to how recently these animals died off.
Although Earth has gone through several extinction events since geologic time began, the Quaternary event is the only one that man was directly responsible for.
The extinction of sabertooth tigers and other Pleistocene megafauna is a stark reminder of the impact that environmental changes and human activities can have on the planet.
Conservation efforts today are focused on limiting the impact of human activities in order to preserve the biodiversity of living species and protect their habitats.
While sabertooth tigers are long gone, we still have modern tigers and other large carnivores that are currently critically endangered due to poaching and habitat loss.
Governments and conservation organizations worldwide are actively working to protect and restore tiger populations.
These include the creation of protected areas for endangered animals, creating laws to prevent poaching, and raising public awareness about the threats faced by these species and what can be done to protect them.
In recent years, advances in genetic research have sparked discussions about de-extinction.
This is the process of bringing back extinct animal species from preserved genetic materials through genetic re-engineering.
Although this concept is still largely theoretical and ethically complex, animals that were alive until relatively recently, such as the saber-toothed cats, are the perfect candidates for de-extinction.
If de-extinction becomes a reality, species like the sabertooth tiger are at the top of the list of animals we may one day see walking in the wild once again.
This is a remote but not entirely impossible scenario in the far future.
Conclusion
The saber-toothed cats are a group of carnivores that dominated Earth’s terrestrial ecosystem as top predators several million years ago.
The Smilodon was the last of this group of incredible animals, and they were alive between 2.6 million years ago and about 10,000 years ago.
Although it isn’t entirely clear why they went extinct, a combination of factors such as climate change, narrow specialization, and human activities may have contributed to their decline and eventual extinction.
The saber-toothed tigers are all gone, but studying the factors that led to their extinction, along with other ice age megafauna, offers valuable insights into the evolution and extinction of species.
By studying them, we can learn more about the various factors that can lead to the decline and extinction of living species today so we can mitigate them.
These lessons will be very valuable for current and future contemporary conservation efforts that will help prevent the loss of extant animal species.
Sources:
- https://en.wikipedia.org/wiki/Smilodon
- https://www.britannica.com/animal/saber-toothed-cat
- https://www.livescience.com/25848-starvation-extinction-sabertooth-cats.html
- https://sciencing.com/plants-animals-quaternary-era-8146713.html
- https://www.mirror.co.uk/news/world-news/reason-behind-sabre-toothed-tiger-8220741
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