Younger Dryas – species survival

At http://cosmictusk.com/sheridan-cave-down-but-not-out/ there is a link to a paper in Current Research in the Pleistocene, 28 (2011), Redmond and Tankersley, 'Species Response to the Theorised Clovis Comet Impact at Sheridan Cave, Ohio' say that of 63 flora and faunal taxa recovered from the boundary layer 52 species of amphibians, plants, fish, mammals and reptiles were unaffected by the Clovis come and still thrive in the immediate vicinity of the cave. Only two species, both large in size, have disappeared, the flat headed pecarry and the giant beaver, while other mammals, including the caribou (also very large) subsequently moved northwards into Canada. This appear to refute the idea a major catastrophe at the younger dryas boundary caused major extinctions of species.