> we can see the decline in North American megafaunal populations long before People used to say that about the K-T event, too. They later stopped saying it.

> we can see the decline in North American megafaunal populations long before People used to say that about the K-T event, too. They later stopped saying it. It is well established that and when the bolide strike occurred, coinciding with lots of interesting phenomena -- extinctions, climate hiccup, continent-spanning fires, platinum dust. Did it cause them all? That takes more work to establish. But we don't have any competing hypothesis. https://sci-hub.se/10.1086/695703 https://sci-hub.se/10.1086/695703 A catastrophically big volcanic eruption in Europe only a century or two before the bolide strike seemed like it might have caused some things, but the timing does not now seem to match. Something similar is true of the K-T boundary, except even overwhelmingly more-catastrophic eruptions blanketed India, and I don't think we know for sure which came first. It is just possible the bolide strike triggered the eruptions. (Certainly the eruption didn't cause the strike.)