[dkga]

What a treasure indeed! I just didn‘t understand why this particular site had so well-preserved soft tissue fossils? I assume it is probably related to the geology of the site during formation of the fossils, and probably the researchers themselves are not quite sure. But I would love to know more, if anyone here understands about this sort of thing.

[arnsholt]

If I had to guess, they probably have some ideas. In Your inner fish (an excellent book, BTW) Neil Shubin has an afterword where he describes roughly how they went about deciding where to look for Tiktaalik. Basically, you start with whatever thing you want to find out more about; in the case of Tiktaalik, the transition of tetrapods from aquatic to terrestrial living. So you start by finding out where you have exposed sedimentary rocks of the correct age likely to be contain fossils. Next, you also need to the rocks to expose the right kind of environment: desert sands or deep ocean environments aren't going to help you find Tiktaalik, for that you need shallow waters and intertidal zones. Finally, it needs to be somewhere you can get to. So in this case, I wouldn't be surprised if they were purposefully looking for soft body preservation (especially since I think Cambrian fauna generally was quite soft and squishy).

From memory, to get fossilised soft tissues you want the remains to be buried extremely rapidly in an environment where the soft tissues don't decay (typically an anoxic environment, so for a shale basically covered in mud). So a mudslide is one option, and I think there are some lovely fossils North American from the end of the Cretaceous that are hypothesised to have been buried by the tidal wave caused by the Chicxulub impact.

Edit: After some googling, the Cretaceous fossils I was thinking of is Tanis,[0] which is in fact plausibly (but not universally) thought to be covered by the earthquake caused by the impact, before the tidal wave arrived.

0: https://en.wikipedia.org/wiki/Tanis_(fossil_site)

[alehlopeh]

Start with whatever thing you want to know more about. Then draw the rest of the owl