An interesting discovery; Rapetosaurus, the Malagasy titanosaur, had the largest osteoderms of any dinosaur known... but they weren´t armor, as was believed. Actually they were hollow, and may have served as a mineral storing device, to help the animal survive during drought and keep growing when food was scarce.
Read about this on Dinosaur Tracking Blog the other day. Pretty good theory. Ostederms like the ones on sauropods struck me as being very ineffective as far as armour was concerned.
Agreed. One would expect the sides, belly and neck to be better protected anyways; few predators were tall enough to bite their back and Majungasaurus in particular (Rapetosaurus' main enemy it seems) actually had very short legs
Very interesting. I have an Idea too. Perhaps they helped by providing floatation for those migrations when they crossed rivers? Unlikely, but hey this is the place to put your way out ideas isn't it?
And No I don't think they helped the beast float, just stay the right way up in deep water.