Hi!
While looking around the steps outside Bilbao's Guggenheim Museum, I came across this which looks a lot like the cross section of a bone?? Unfortunately I have no information as to where this rock was quarried, so I don't know how old it is... I'm attaching another photo to show the other kind of fossils that can be seen on the steps. I assumed they were some kind of marine creatures (rudists maybe, which I'm used to seeing in other parts of the city, in a different type of rock), which is why a bone seems a bit crazy.
It would be nice to know what you guys make of it! :-)
Thanks!!
Elizabeth