10-11-2006, 12:00 AM
Smilodon Populator was a lion-sized cat, extremely strong and powerful (particularly in the chest and forelimbs; an adaptation designed for its large-sized prey) and armed with 7-inch long sabre-teeth. Some debate has taken place on exactly how these were used. Some people suggested they were for climbing trees, others for punching through the skull of the prey, and still others claimed they were used to stab into the throats of the herbivores. Calculations indicated that the teeth were not strong enough for the first two applications - they would have shattered when they impacted bone, and this also ruled out the neck-bite technique used by the extant small cats. The 'stab' theory didn't hold water, either, as the cat's neck and jaw muscles were not powerful enough to propel the teeth through the thick hide.
The rear edges of the sabres are serrated, and this indicated that the cat used its teeth as blades to cut through the hide and tissues of its prey, rather than as daggers. The smaller lower canines were driven into the hide of the prey animal's neck or belly, to provide purchase for a downward strike by the sabres as the cat closed its jaws (this action is termed a 'shearing bite'). Evidence for this is the fact that Smilodon's jaws could open 25 degrees wider than those of the modern cats, allowing it to achieve a similar clearance between the tips of upper and lower canines as modern cats. By using this technique, the teeth would never encounter bone. The prey animal would then die of blood-loss. The problem with this explanation is that any torsional loads on the teeth, for example the movements of a standing prey animal, would break them. So Smilodon could not have brought down its prey using its teeth alone. It is probable that hunting took place in groups, and the upper-body strength of the cats was used to capture and restrain the prey before the fatal bite was applied to the throat.
One of the advantages of the sabre was that prey carcasses could be sliced up and carried back to the den to feed young, eliminating the need for the young cubs to accompany their mother. There is some evidence that Smilodon may have lived in a pride social structure. The Rancho La Brea asphalt pit fossils indicate that for every trapped herbivore, several Smilodon are present, leaving pack-hunting a likely scenario. In addition, the Sabres' teeth were so large that they did not fully develop until the animal was quite mature, so the level of maternal care required over a long period would have been high. This would suggest social groupings were the norm.
Smilodon Populator lived in the east of South America, and other (slightly smaller) species of Smilodon lived in North America. Its body was in some ways different from the lion; relatively, it had shorter hind- and longer fore-limbs, giving it a stance more like that of a hyaena. This would have allowed it to run more easily, and so chase prey over long distances. In contrast, the modern lion will not usually sustain a chase beyond a few hundred metres.
The Sabre-tooth design was predominant among the cats until 5-6 Ma, when climate change resulted in the forests which had covered the continents giving way to open savannah and plains. This in turn led to the proliferation of smaller herbivores, such as antelope and gazelle, which could outrun the Sabre-toothed cats easily. It was at this point that the Pantherines evolved, from which descended many of the larger cats of today, with smaller teeth and other adaptations to the new prey species.
The Sabre toothed cats were still able to survive, as the mega-herbivores were still in existence, but around 35,000 years ago further climate change led to colder weather. This saw the demise of the mega herbivores, and so the sabre-toothed cats. The evolution of hominids, who hunted with weapons, and competition from pantherine species such as the lion (which evolved only 600,000 years ago) lead to their final downfall.
The rear edges of the sabres are serrated, and this indicated that the cat used its teeth as blades to cut through the hide and tissues of its prey, rather than as daggers. The smaller lower canines were driven into the hide of the prey animal's neck or belly, to provide purchase for a downward strike by the sabres as the cat closed its jaws (this action is termed a 'shearing bite'). Evidence for this is the fact that Smilodon's jaws could open 25 degrees wider than those of the modern cats, allowing it to achieve a similar clearance between the tips of upper and lower canines as modern cats. By using this technique, the teeth would never encounter bone. The prey animal would then die of blood-loss. The problem with this explanation is that any torsional loads on the teeth, for example the movements of a standing prey animal, would break them. So Smilodon could not have brought down its prey using its teeth alone. It is probable that hunting took place in groups, and the upper-body strength of the cats was used to capture and restrain the prey before the fatal bite was applied to the throat.
One of the advantages of the sabre was that prey carcasses could be sliced up and carried back to the den to feed young, eliminating the need for the young cubs to accompany their mother. There is some evidence that Smilodon may have lived in a pride social structure. The Rancho La Brea asphalt pit fossils indicate that for every trapped herbivore, several Smilodon are present, leaving pack-hunting a likely scenario. In addition, the Sabres' teeth were so large that they did not fully develop until the animal was quite mature, so the level of maternal care required over a long period would have been high. This would suggest social groupings were the norm.
Smilodon Populator lived in the east of South America, and other (slightly smaller) species of Smilodon lived in North America. Its body was in some ways different from the lion; relatively, it had shorter hind- and longer fore-limbs, giving it a stance more like that of a hyaena. This would have allowed it to run more easily, and so chase prey over long distances. In contrast, the modern lion will not usually sustain a chase beyond a few hundred metres.
The Sabre-tooth design was predominant among the cats until 5-6 Ma, when climate change resulted in the forests which had covered the continents giving way to open savannah and plains. This in turn led to the proliferation of smaller herbivores, such as antelope and gazelle, which could outrun the Sabre-toothed cats easily. It was at this point that the Pantherines evolved, from which descended many of the larger cats of today, with smaller teeth and other adaptations to the new prey species.
The Sabre toothed cats were still able to survive, as the mega-herbivores were still in existence, but around 35,000 years ago further climate change led to colder weather. This saw the demise of the mega herbivores, and so the sabre-toothed cats. The evolution of hominids, who hunted with weapons, and competition from pantherine species such as the lion (which evolved only 600,000 years ago) lead to their final downfall.