<Li> A site in Walker, Minnesota with stone tools, alleged to be from 13,000 to 15,000 years old based on surrounding geology, was discovered in 2006 . However, further examination suggests that the site does not represent a human occupation . </Li> <Li> In a 2011 article in Science, Waters et al. 2011 describe an assemblage of 15,528 lithic artifacts from the Debra L. Friedkin site west of Salado, Texas . These artifacts (including 56 tools, 2,268 macrodebitage and 13,204 microdebitage) define the Buttermilk Creek Complex formation, which stratigraphically underlies a Clovis assemblage . While carbon dating could not be used to directly date the artifacts, 49 samples from the 20 cm Buttermilk floodplain sedimentary clay layer in which the artifacts were embedded were dated using optically stimulated luminescence (OSL). Eighteen OSL ages, ranging from 14,000 to 17,500 ka were obtained from this layer . The authors report "the most conservative estimate" of the age of the Buttermilk clays range from 13,200 to 15,500 ka, based on the minimum age represented by each of the 18 OSL ages . </Li> <Li> Human coprolites have been found in Paisley Caves in Oregon, carbon dated at 14,300 years ago . Genetic analysis revealed that the coprolites contained mtDNA haplogroups A2 and B2, two of the five major Native American mtDNA haplogroups . </Li> <Li> The Mud Lake site, in Kenosha County, Wisconsin consists of the foreleg of a juvenile mammoth recovered in the 1930s . Over 100 stone tool butchering marks are found on the bones . Several purified collagen AMS dates show the animal to be 13,450 RCYBP with a range of plus or minus 1,500 RCYBP variance . </Li>

Which of the following was characteristic of the clovis culture