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It is possible that if they tell us about the famous "saber teeth" we imagine the friendly Diego, the saber tooth tiger from "Ice Age, the ice age". While it is true that this term is used to refer to several species of Cenozoic felids, the best known is the Smilodon. Do you want to know what life was like for these animals? Their main characteristics? And, most important of all, do you want to know why they became extinct? In Green Ecologist we are going to introduce you to these big cats and collect the various theories about why did the saber teeth go extinct.
Saber tooth tigers
"Saber teeth", as we have mentioned, is a term that is used generically to refer to various species of mammals characterized by the presence of large canines that protrude on both sides of the mouth and that lived at different times during the Cenozoic.
Despite their name, they are not related to the tigers that we know today, but they were compared to them due to their large size (somewhat smaller than lions). Saber teeth belong to the subfamily Machairodontinae, while the current tigers and lions belong to the subfamily Felinae, both of the family Felidae. Macairodontins and felines have a common origin in the Upper Oligocene (23 million years ago), the period in which the first known feline lived: Proailurus.
This subfamily includes several extinct genera, and among them highlights the popular Smilodon. They owe their name "saber teeth" to the curved and elongated shape, similar to that of sabers, of their fangs; homologous to those possessed by the rest of the felids. Smilodon it was characterized by being the genus with the largest canines, reaching up to 20-26 centimeters, both in males and females, in the case of the species Smilodon populator. Other famous species are S. fatalis or S. gracilis.
Thanks to the fossil record, it was determined that saber teeth inhabited throughout the American continent. In addition, it was estimated that they measured between 1-1.1 meters in height and that a specimen could reach 300 kilograms.
How they used their big fangs
The felines kill their prey by suffocation, biting them in the throat or snout to prevent the passage of air to the lungs and, only when the prey are small, does the bite occur on the head or neck to break the bones of the skull or vertebrae in the cervical area.
However, saber tooth fangs were susceptible to breaking if used to bite into bone tissue, which is why they specialized in large prey (small prey carried a greater risk of striking their bones and causing the rupture of fangs). It is strange to think that despite the large size of these structures, they made the saber tooth bite less powerful. Surprisingly, the effectiveness lay in the angle that they could reach when opening the jaw, reaching up to 120º of opening (the current lion reaches 65º).
Unlike the felines, the Macairodontins did not seek to kill their prey by suffocation (which would suppose a great energy expenditure due to the need to immobilize the prey and maintain the bite until it died asphyxiated). The most widespread theory about the utility of these big fangs in saber teeth was the hunting large prey from below to catch the throat and section it. The curved and very sharp fangs penetrated the victim, neutralizing him much more quickly than by suffocation. Some specimens even had the edges of the serrated tusks so that the cut produced a faster and cleaner incision, reducing the energy cost that occurred during hunting and the possible risks posed by the prey (kicks, horns). Thus, the role of the canines stands out, that of tearing, a function that is increased when the prey is held and immobilized on the ground. On the other hand, it is believed that in addition to blocking their respiratory flow these canines they also cut the main blood vessels that lead the blood to the brain, causing the prey to lose consciousness even before dying, ceasing to pose a threat.
In the event that the prey escaped before being immobilized, it would quickly bleed out from the bite. As a consequence it dies and the saber tooth is able to recover it later.
Other characteristics of saber teeth
In comparison to felines Saber teeth today had other characteristics such as:
- They were not great runners because of their stout build and the length of their tail, only 35 centimeters long, which in existing cats is long and serves to maintain balance during the race.
- They had a much more developed sense of smell.
- They had a small brain.
- His limbs were very muscular and powerful.
- Retractable paws, a quality they share with cats, but not with tigers and lions.
- They lived in packs. It is thought that they cared for members who were injured or sick.
The extinction of the saber teeth
The gender Smilodon silenced their roar at the end of the Pleistocene, the last ice age of the Quaternary, that is, the saber teeth became extinct 12,000-10,000 years ago.
Drastic environmental and climatic changes occurred that could generate a cascade of consequences in the food chain of saber teeth. One of these consequences was that the distribution of large prey became much more errant (in 5,000 years there was an increase in temperature of more than 6º, which could have a negative influence on said distribution), making it difficult for the teeth to hunt. saber.
These climatic changes caused the retreat of the glaciers, as well as the change of the seasons and the increase in rainfall, which influenced and altered the local ecosystems. But nevertheless, Smilodon It had survived other glacial periods before, so there must have been an added factor that differentiated it from previous climatic events, such as changes in temperature and vegetation. The latter changed so that made it harder for felids to stalk to their prey and coexist with other predators. Thus, the competition between various species of carnivores was very violent.
To all this was added the arrival of the first hominids to the American continent, where saber teeth were distributed. Humans were able to contribute to their extinction by hunting large mammals (such as mammoths, mastodons, moose or bison) that were common prey for saber-toothed teeth.
Finally, during the most abrupt climatic changes at the end of the Quaternary, ecosystems were not capable of harboring and maintaining all the diversity of large predators, so that less specialized and flexible species increased their chances of survival. It was then that the cats had an advantage and finally, they succeeded the macayrodontines.
A new advance on its extinction
Based on the previous section, we can say that the extinction of the saber teeth could have occurred, broadly speaking, due to the shortage of prey due to climatic changes and competition with other predators. Scientists at Vanderbilt University have developed research that may help clarify this fact1.
The study in question analyzes fossilized remains through a technique called “tooth texture micro wear analysis” (developed by study co-author Peter Ungar of the University of Arkansas). The director of the study, Larisa DeSantis, shares that in situations where food is scarce, today's felines consume a greater part of the carcass of the prey, including its bones. When this happens, the teeth have large and deep grooves, as opposed to those that have chewed only meat, which show small marks in parallel.
The analysis revealed that the saber teeth had wear patterns similar to that of the African lion current, he chews some bones when he eats. Despite all this, they found no evidence as to whether they used corpses to a greater extent throughout the period in which they existed, but the analysis suggested that the proportion of corpses they consumed decreased towards the end of their existence.
If you want to read more articles similar to Why Saber Teeth Are Extinct, we recommend that you enter our category of Extinct Animals.
References- DeSantis LRG, Schubert BW, Scott JR, Ungar PS (2012) Implications of Diet for the Extinction of Saber-Toothed Cats and American Lions. PLoS ONE 7 (12): e52453. https://doi.org/10.1371/journal.pone.0052453
