That’s a tough question for me. I love fossils! Probably if I have to pick just one, then it’s one of the ginkgo fossils that I worked on for my phd a few years ago. I have a picture of this fossil up on my profile. It’s 201 million years old and you can still see the original squished leaf – it’s pealing off the rock. We call this a “compression” fossil because it’s been squished between layers of rock to be preserved. Underneath you can see the impression of the leaf – this is another way that fossils can be made. That particular fossil is really beautiful and was an important part of my work.
I also saw dinosaur eggs in Romania and they were really cool, and I have seen some amazing fossil insects too. I recently got a fossil fish that’s about 50 million years old and you can see all of its little bones, very cool too.
Really I think that the coolest fossils are just all fossils!