I also notice you can't see the bones unless your looking at your map. Also you can't go through some areas that are shown in the map so my conclusion is that there was more to this but the developer eliminated this maybe for another elder scroll? I was thinking that it could be a big ancient whale or lorkhan bones since its close to morrowind where his heart was cast. Cause I know his body are the two moons. I just thing is coincidence that its close to shor stone,morrowind and in a dwemer place close to the sovengarde gate where *spoilers* alduin soul is taken and his body ripped apart.
What do you guys think? Mammoth? Whale? Scraqed content? If you zoom all the way in while looking at the map you will realize how big they truly are. I think there iis about four pieces and a ring bones in the middle.