Cienciaes.com: Smilodon populator, the South American saber-toothed tiger.

2010-11-09 07:06:13

Saber-toothed tigers of the genus Smilodon (“chisel-tooth”) appeared about two and a half million years ago in North America. The oldest species, Smilodon gracilis (“gracile chisel-tooth”), weighed between 50 and 100 kilos, and lived in North America until half a million years ago. It was replaced by Smilodon fatalis (“fatal tooth-chisel”), which lived from a million and a half to about 12,000 years ago, and spread throughout western South America; It was one meter tall at the withers and weighed between 150 and 300 kilos, more or less like a Siberian tiger. But an even larger species, Smilodon populator (“devastating chisel-tooth”), appeared a million years ago in South America, east of the Andes.

It was the Danish paleontologist Peter Wilhelm Lund who, in 1841, described the species Smilodon populator from the fossil bones he had discovered in caves near the town of Lagoa Santa, in southeastern Brazil. It is the largest saber-toothed cat that we know of, with a height at the withers of 1.25 m, 2.6 meters in length and an estimated weight of between 360 and 500 kilos.

The upper canines, thirty centimeters long, protrude about seven centimeters from the mandible. They are curved, with a serrated posterior edge. Unlike the canines of current cats, which are conical, those of Smilodon are oval in section, longer than wide, which makes them more fragile; impact with a bone could break them. Thus, the animal had specialized in hunting animals larger than itself, with large soft parts to feed on. Their hunting technique was also different from what today’s cats use. They strangle their prey with a bite to the neck, which entails a fight of several minutes. This fight, in the case of Smilodon, could be fatal to its fangs, so the saber-toothed tiger, with its muscular front legs, first immobilizes the trunk and head of its prey and then slits its throat, severing the windpipe and the jugular of a bite, with which death is almost instantaneous.

Smilodon bones with healed lesions have been found, indicating that the animal lived in packs, where healthy adults cared for and fed injured or sick individuals.