Interesting question.  Apparently, yes for both taxa.

Doing a brief scan on the interweb revealed these sources.  I cannot validate the accuracy of this information.  Interesting topic though.  I imagine that crustose lichens would be easily fossilized as oppose to the soft thalli counterparts.  There's probably some encased in amber or impressions in certain rock through the carbonization process or casts/molds of buried organism.

https://ucmp.berkeley.edu/fungi/lichens/lichenfr.html

https://nph.onlinelibrary.wiley.com/doi/10.1111/nph.12009

https://ucmp.berkeley.edu/fungi/fungifr.html

-Lin

Thank you both for the info! I'm amazed they can be fossilized. Pretty cool!

I had a student who did a research project and determined that there are only about 150 total verified lichen fossils and about half of those are from one site.

Do the orange spots on the limb in my photos look like lichens? Or maybe some kind of fungus? Or just some oddball thing that happened when the limb was silicified?

I don't know as I've seen bark stacks but the background around these spots doesn't look like pine bark at all to me. They're all around 1-1.5 cm across.