...There is no global evidence of a disaster of this magnitude at all, and we're good enough that we can see global evidence of massive meteor strikes or supervolcano explosions from millions of years ago (for example)

“Many of these animals appear to go out 12,900 years ago after a preceding and catastrophic event. In fact, this stratum of nanodiamonds – the sediments containing these nanodiamonds – in some cases sit directly above the bones of these extinct animals. These animal bones do not occur above the sedimentary layers in well-stratified sections.

“Nanodiamonds only form under very high temperatures and pressures consistent with a major cosmic impact event. It’s very hard to explain their presence in these sediments just based on other kinds of surficial processes. And, of course, increased temperatures and pressures would have had major repercussions for the environment in North America, including vegetation and animals and humans that were on the landscape at the time.

“The destruction would have been instantaneous. People living in the immediate vicinity of impact or airbursts would pretty much have been annihilated. And where the impacts and airbursts would have occurred, there would have been a lot of debris kicked up into the atmosphere. And I can imagine there would have been major sound – even hard to imagine the senses that would have been involved in all this. Also, the wildfires triggered by all this would have put smoke and soot up into the atmosphere that would also have had major atmospheric effects in terms of obscuring the sun for fairly long periods of time.”