John Carlos Baez on Nostr: We know there was an asteroid impact around when the dinosaurs went extinct 65 ...

We know there was an asteroid impact around when the dinosaurs went extinct 65 million years ago because we see a rare metal called iridium in the strata from this time - and droplets formed by molten quartz.

But we also see lots of fern spores! This is called a 'fern spike', and it's not the only one. Ferns spread rapidly using spores, and were the first to recolonize the land after the Cretaceous-Paleogene and Triassic-Jurassic extinction events.

I like ferns. Knowing this makes me like them even more.

Thanks to Nicole Parsons (npub174q…ckk8) for telling me about fern spikes. Read more here: Nicole Parsons (npub174q…ckk8)/117201753504722650">https://mathstodon.xyz/Nicole Parsons (npub174q…ckk8)/117201753504722650