I found this bone in Auvergne as a child. This specific area is apparently well-known to paleontologists and I found the bone in a field very close to scientific excavations (literally meters away from the area that was delimited by ropes). I picked it up and brought it to a local museum but back then they simply told me something like "lucky find, it might be a prehistoric animal! You can keep it, we only do mammoths here."
Years passed and I've kept this bone (probably a vertebra, coccyx or sacrum) on a shelf. Now, my curiosity is having the best of me and I would really like to identify it.
I spent some time looking at "bone identification" forums, databases and charts online, but they were quite disappointing. However, I am almost sure the bone belongs to the spine of a mammal.
Here are pictures (mug for scale):