Oh poor dears, they did make a great find but they just keep missing the truth that all those creatures were buried in the Flood of Noah, not evolved, and "after" the dinosaurs not in great aeons of time, but only in the sense that they were buried above them.
So in this case instead of the bones getting fossilized by the replacement of bone material with a fossilizing mineral this mineral collected AROUND the bones instead and built up a rounded casing for them? So inside these concretions are unfossilized bones? Why the different process?
AbE watched it again. There's one point where they say the bones were ALSO fossilzed so I guess that answers my question. Why they also formed this ball of mineral within the rock is still a question though.