Sabre-toothed Tiger
ExtThe "sabre-toothed tiger," Smilodon, is the California State Fossil and the second most common fossil mammal found in the La Brea tar pits. The name "sabre-toothed tiger" is misleading, for these animals are not closely related to tigers. Juveniles to adults are represented in the large Berkeley collections. The first Chairman of the University of California Department of Paleontology, Professor John C. Merriam, and his student Chester Stock, monographed the morphology of this great carnivore in 1932. Since then, hundreds of thousands of Smilodon bones have been found at La Brea, permitting remarkably detailed reconstructions of how Smilodon lived. For example, Smilodon was about a foot shorter than living lions but was nearly twice as heavy, and unlike cheetahs and lions -- which have long tails that help provide balance when the animals run -- Smilodon had a bobtail. These suggest that Smilodon did not chase down prey animals over long distances, as lions, leopards, and cheetahs do. Instead, it probably charged from ambush, waiting for its prey to come close before attacking.
Smilodon was a relatively recent sabretooth, from the Late Pleistocene; it finally went extinct about 10,000 years ago. Fossils have been found all over North America and Europe. Smilodon fossils from the La Brea tar pits include bones that show evidence of serious crushing or fracture injuries, or crippling arthritis and other degenerative diseases, that would have been debilitating for the wounded animals. Yet many of these bones show extensive healing and regrowth, indicating that even crippled animals survived for some time after their injuries. How did they survive? It seems most likely that they were cared for, or at least allowed to feed, by other sabre-toothed cats -- solitary hunters with crippling injuries would not be expected to live long enough for the bones to heal. Smilodon appears to have lived in packs and had a social structure, like modern lions but unlike tigers and all other living cats, which are solitary hunters. Occasional finds of sabretooth-sized holes in Smilodon bones suggest that the social life of Smilodon was not always peaceful; the cats may have fought over food or mates, as lions do today. Such fights were probably accompanied by loud roaring -- from the structure of the hyoid bones in the throat of Smilodon, we know it could roar.