The Younger Dryas impact hypothesis: a cosmic catastrophe

@article{Holliday2014TheYD,
  title={The Younger Dryas impact hypothesis: a cosmic catastrophe},
  author={Vance T. Holliday and Todd A. Surovell and David J. Meltzer and Donald K. Grayson and Mark Boslough},
  journal={Journal of Quaternary Science},
  year={2014},
  volume={29}
}
In this paper we review the evidence for the Younger Dryas impact hypothesis (YDIH), which proposes that at ∼12.9k cal a BP North America, South America, Europe and the Middle East were subjected to some sort of extraterrestrial event. This purported event is proposed as a catastrophic process responsible for: terminal Pleistocene environmental changes (onset of YD cooling, continent‐scale wildfires); extinction of late Pleistocene mammals; and demise of the Clovis ‘culture’ in North America… 
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Late Quaternary megafaunal extinctions on the continents: a short review
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TLDR
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