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Death by Design
Explaining the function and failure of a Weapon designed by Nature
How did the Saber Tooth evolve? How many species of animals sported saber teeth? Why arent there anymore Saber Tooth beasts? This is a question that needs to be addressed in a proper perspective. For years scientist have focused on designer weapons evolved by beasts through out the ages with a foggy vision. They have often made the mistake of tracing the origin of the weapon through solitary evolution via one particular species. The problem in doing this is the side effect of leaving more potent theories out of the initial perspective. It is my opinion, that on certain extreme traits featured on various animals, one should consider the entire spectrum of beings that share a similar trait. Whether the feature is due to a direct genetic ancestor, or shaped by the grand design of convergent evolution, the main prospects of these features should be taken into account. With this in mind, an observant student can gain a greater deal of information concerning the function of any particularly prominent trait.
In this case, we are examining the function and related issues of the Saber-tooth. When I mention Saber Tooth, I dont just mean the Saber Tooth cats, but a great host of prehistoric beasts that wielded this awe-inspiring design. The extreme extension of canine teeth had occurred much earlier than most expect. In fact, saber teeth were already being established before the true rise of the dinosaurs. Ironically, this advantageous design was well in demand during the early and mid-Triassic period via the mammal-like reptiles known as Therapsids. Later, this design would establish itself in the carnivorous marsupials and finally in the true placental mammals.
In the Therapsids these large teeth were not as long as the later saber-toothed animals that would evolve later. However, there can clearly be seen the evolution of the extension of certain teeth that would somewhat awkwardly serve as bone swords to slice and puncture their prey. These mammal-like reptiles served as an intermediate form between both reptiles and mammals. Some people even speculate that Therapsids should be classified in another category altogether. Unlike the extensive studies made in determining how cats used saber teeth, little is known on how Therapsids wielded their toothy sabers. But saber teeth as a concept must share similar purposes. We do know they were used in hunting and eventually killing their prey, but why they evolved in creatures so different from one another is often debated.
A Saber-tooth What? A new look into other Saber-Tooth Beasts
Therapsids, Marsupials, and Placental Mammals do share quite a bit of history. Therapsids are considered the true descendants of Marsupials, Monotremes, and placental mammals, but despite this fact, there are huge differences in their genetic makeup that separates them distantly apart. This brings to mind the conclusion that saber teeth may have evolved from the species lifestyle, but does this admission place the existence of the Saber Tooth phenomenon among the ranks of convergent evolution?
During the illustrious reign of the Therapsids, dinosaurs were not the dominant species. Therapsids did exist during the dinosaurs dynasty later in the Jurassic, but with little success as a species. However, the Triassic was largely dominated by these possibly warm blooded, beasts. The competition that faced them came in the form of new and varied reptiles such as the Archiosaurs and Poposaurrids. Displaying clear mammalian features, Therapsids seem to be the focal point of origin regarding the evolution of saber teeth. So, does this mean that saber teeth are a mammalian trait?
Most would agree that saber teeth are indeed a mammalian or pre-mammalian trait. In South America just over one and a half million years ago, a battle between the best-evolved saber teeth may have occurred. South America is considered by most, the launch pad of the evolutionary line of marsupials. Marsupials evolved along a parallel path to the placental mammals that lived to the north of them, but they have adapted to their environment just as well as their northern cousins. However, native predatory marsupials from South America would soon find themselves in a competition for turf and prey. A Saber Tooth marsupial called Thylacleo was among a number of large Saber Tooth marsupials to feel the pinch of some new Saber Tooth invaders.
As the sea level changed, new land bridges began to appear. These land bridges gave northern placental mammals an opportunity to migrate toward South America. Unlike most, I believe the placental predators that arrived in South America were actually following their northern herbivorous preynot looking for new prey.
However, they did find new prey and some of those species were not well prepared for these new carnivores. The aspect of saber teeth reached two forms in the marsupials--one type of marsupial sported huge sword-like teeth from both sides of its hinged jaw (much like the Saber Tooth cats), while another species had long serrated sabers that sprouted from its top and bottom front teeth. These predators had earlier been cast as rather witless and less successful carnivores than the more highly regarded placental predators, but this is far from the truth!
Though the presence of Saber Tooth marsupials existing in the same era and same territory as the Saber Tooth cats that traveled to South America may be in dispute, there is no doubt that at least some of them eventually collided with one another. Predatory marsupials did reach some fearsome sizes. Some were as large as a mountain lion and they had brain sizes as large, or in some cases, larger than many placental predators.
This leads to the conclusion that the Saber Tooth marsupials were in fact very successful as predators. However, they began to dwindle in numbers when the Saber-tooth cats finally arrived (in full population) within South Americas humid savannas.
Oddly enough, the native Saber Tooth marsupials already had witty competition in the form of huge Terror Cranes. These ten-foot tall birds were the scourges of many mammals in prehistoric South America. Ironically, it is thought that these feathered terrors ate the same prey species that the marsupial predators vide for. But were saber teeth a true advantage? The marsupial saber tooths had existed for a long time before the new Saber Tooth cats arrived. They even competed successfully against large carnivorous birds, but when the cats came strutting into their territory things began to change. Smaller cats without saber teeth were also in tow toward South America, but the Saber Tooth cats seemed to be the main culprit in diminishing their marsupial counterparts food supply. Was competition from other Saber Tooth beasts too much for the hardy Saber Tooth marsupials?
The emergence of Saber-tooth cats in North America and abroad had an influence on the food chain through out the Old World. Although there were bigger cats than saber tooth, such as cave lions, their distribution had mainly placed them in different climates and territory. Long ago California looked much like todays African plains. It is thought that the saber tooth lived a very similar life to modern lions. However, there was also some very leopard like saber tooth as well, and like the comparison they probably lived much like leopards. One species of Saber Tooth called Smilodon had become the very epitome of what Saber-tooth cats were all about!
The Cats got your Tongue
Smilodon was a particularly large Saber Tooth, but even so stood only slightly larger than todays African lions. However, the Smilodon was constructed differently and boasted a much more stocky and powerful build. Smilodon seemed to have a lot of muscle dedicated to the front portion of its body...mainly the shoulders and neck. This was probably due to the animals killing technique. Smilodon has been in much controversy about how these beasts used their huge saber teeth. It is now widely believed that they used their sabers to cut through the animals main artery while choking the animal prey in the process. Having large muscles on the shoulder and neck helped them to secure the prey as well as use their powerful sabers to impale the struggling animal. This leads to my new theories regarding why the Saber Tooth design disappeared from the earth.
Why hasnt any modern cats developed saber teeth? Why doesnt a lion or tiger have saber teeth today? Besides this, why doesnt any other predator hang on to this design? Isnt it true that there are no Saber Tooth wolves and no Saber Tooth bears, and certainly no longer any Saber Tooth marsupials, but why? Beside the walrus, which has two very long protruding saber-like teeth, (now considered tusk) there are no saber-toothed animals existing today. We already know that the developments of such specialized weapons are not restricted to a specific species. In fact convergent evolution seems to favor the design, but what is the missing component that induced the evolution of saber teeth?
To tackle this problem one must look at the dilemma in a broad and general view. What was the common trait in the lifestyles of various Saber Tooth animals? Hunting is surly one trait, but more specifically there was probably a more pinpoint aspect to themspecialization. When an animal develops a specialized feature, its usually due to a long lasting set of circumstances that have adapted the animals to live a particularly advantageous life in that certain niche.
Saber tooth animals have become specialized in taking down prey. However, it has occurred to me, that saber teeth may have evolved to kill only a certain number of prey species. Imagine a Saber Tooth cat like Smilodon killing a rabbit. Certainly they must have dined on small prey occasionally, but killing small animals with such large saber teeth is like shooting a fly with a shotgun! --In plain terms, its simply overkill!
Saber teeth, among many types of animals, seem to be advantageous only in killing a prey species of designated structure. It is known that in both North America and South America, large horse-sized herbivores grazed the lands. These animals, though not related, did have similarities. In fact, they had somewhat elongated necks and even more similar bodies.
So, it is easy to see how saber teeth could become an advantageous trait in hunting prey that shared many of the same features. In North America long necked camels were thought to be one of the primary prey species for Saber Tooth cats. Ironically, the similar looking species of Macromeannia served as the main prey species to both the saber tooth cats, and large marsupial predators down in South America. This idea supports the reasons as to why the Saber Tooth cats were so successful when migrating down to South America.
Thinking in this manner does raise another question altogetherIf the evolution of saber teeth is directly due to the specialized feeding of certain prey species, does this mean that the disappearance of once abundant prey account for the demise of the Saber-Toothed? Well, essentially--Yes! Though a theory is little more than a well-constructed hypothesis, and a hypothesis is little more than an educated guess, the possibility of such a conduit for the decline of all Saber Tooth animals certainly seems to hold!
However, I want to make sure that I am not misunderstood on this theory. I am not saying that the decline of specialized prey species accounts for the extinction of Saber Tooth animals. Instead, I state that the disappearance of certain large prey species (constructed similarly) had a strong impact on the advantage once held by all Saber Tooth animals. So with this in mind, I believe the extinction of the actual saber tooth design fell victim to extinction, but not necessarily the animals themselves! In contrast, it is also a possibility that the Saber Tooth animals may have simply evolved to lose the saber teeth that no longer posed as an advantageous trait and thus began to evolve into other species.
In conclusion, it is wise to consider other possible theories that may attribute to the evolution or de-evolution of specialized traits and features of a species. Consequently, the Saber Tooth design, though no longer apparent in modern species, may well evolve again. Perhaps, some time in the future when this formidable design deems to once again pose a great advantage in the most basic of hunting skillsthe kill!
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