study this week that re-examined the Clovis-aged Murray Springs archeological site in southeastern Arizona, and concluded that it does not support the hypothesis that an extraterrestrial impact caused the late Pleistocene megafaunal extinctions (such as mammoths, saber tooth cats, giant ground sloths and Dire wolves – along with the Clovis hunter-gatherer culture some 13,000 years ago).
[right, fossil locale southeast of the Murray Springs Clovis site. Credit: C. Vance Haynes, Jr., courtesy of the Center for the Study of the First Americans]
Ref: The Murray Springs Clovis site, Pleistocene extinction, and the question of extraterrestrial impact, C. Vance Haynes Jr., J. Boernerb, K. Domanikc, D. Laurettac, J. Ballengerd, and J. Gorevac, Proceedings of the National Academy of Science (PNAS)
[taken from the UA news release]