Crinoids are marine animal (not plants) that have been around since the late Cambrian, some 500 million years ago. Crinoids usually have a stem used to attach themselves to a substrate, but many live attached only as juveniles and become free-swimming as adults. They are very fragile and require specific conditions to be preserved, so fossils like this one are very rare indeed.
Andrei's background is in geophysics, and he's been fascinated by it ever since he was a child. Feeling that there is a gap between scientists and the general audience, he started ZME Science -- and the results are what you see today.