It's amazing to think of how alien the Earth has been in the past. I think we humans tend to fall victim to this idea that the world we first experienced is how things "are" or "should be" when in reality there's no baseline at all. The EArth has been frozen to the equator (~500M years ago). Sea levels have been higher. They've also been significantly lower and quite recently too (eg there are Neolithic artifacts in the English Channel because that was a land bridge 10-50,000 years ago).

My favourite example: for the first 60M years of trees existing, there were no organisms to digest the wood of dead trees. They just sat there or maybe burned. This is where 95% of the coal comes from.

I'd really give anything to see some of these periods all the way back to the Cambrian Explosion, which had some truly alien-looking life based on fossil records.

It's also why I'm skeptical about doom and gloom predictions of runaway climate change. To be clear, I'm a firm believer that human activity has played and will continue to play a huge part in climate change. This also may be really bad for us. But the Earth will (ultimately) be fine. Something like 99% of the species that have ever existed are extinct now and this will continue to happen with or without human involvement.

The article points out that DNA degrades quickly (~500 year half life). That doesn't mean it can't survive for millions of years. It just means very little of it does. Also environmental factors come into play (eg it would probably survive longer in Antarctica, for example). Still, recovering a complete genome from such fragments is all but impossible (also mentioned).

Anyway, It's kind of amazing to think that a mosquito bit some creature ~46M years ago and a fossil of it somehow survived until today.