Answer:
The Ray- Finned Fish has a bony skeleton just like crocodiles. Crocodiles evolved more and adapted to their environment. Along the way Crocodiles grew to have four limbs, were born from an amniotic egg, and then their eggs also have shells, unlike the Ray-finned fish. Therefore the three characteristics they do NOT have in common are: Four Limbs, Amniotic Egg, and Eggs with Shells. The one trait they do have in common is Bony Skeletons. They also both have vertebrae.
The answer I believe is- Dominant Gene
Yes, I believe they are. If you are talking about us humans finding fossils then no. There are many fossils, bones and other interesting things still to be found