Smilodon likely lived in closed habitats, such as forests and bush, which would have provided cover for ambushing prey. Its reliance on large animals may have been the cause of its extinction; Smilodon died out at the same time that most North and South American megafauna disappeared, about 10,000 years ago. Scientists debate over whether Smilodon had a social or a solitary lifestyle; analysis of modern predator behavior as well as of Smilodon's fossil remains could be construed to lend support to either view