One of the most intense debates in the paleosciences in recent years has focused on the question of whether or not a cosmic impact (comet) approximately 12,900 years ago caused both the Younger Dryas climatic oscillation and the disappearance of Pleistocene megaauna in North America. Since it was frst advanced in print by Firestone et al. (2007), the Younger Dryas Boundary (YDB) impact hypothesis has received an array of challenges from archaeologists and paleoenvironmental scientists (e.g., Buchanan et al. 2008; Collard et al. 2008; Daulton et al. 2010; Fiedel 2009; Gill et al. 2009; Gillespie 2009; Hamilton and Buchanan 2009; Haynes 2008; Meltzer and Holliday 2010; Paquay et al. 2009; Pinter and Ishman 2008; Surovell et al. 2009; see also Kerr 2010), while at the same time, empirical evidence supporting the event has continued to accumulate (Anderson 2010; Anderson et al. 2008; Anderson et al.2011; Andonikov et al. 2011; Bunch et al. 2010; Fayek et al. in press;Firestone 2009; Firestone et al. 2010; Ge et al. 2009; Haynes et al. 2010;Israde-Alcántara et al. in press; Kennett et al. 2009a, 2009b; Kennett,Kennett, West, et al. 2008; Kurbatov et al. 2010; Mahaney, Kalm,Krinsley, et al. 2010; Mahaney, Krinsley, and Kalm 2010; Mahaney et al.2011; Marshall et al. 2011; Napier 2010; Schroeder 2009; Steele 2010;Tian et al. 2011; Van Hoesel et al. 2011), including a large impact crater found off the east coast of Canada dated to about 12,900 years ago (Higgins et al. 2011).
— Contemporary Issues in California Archaeology, 2012