I went to a small ‘dinosaur museum’ last summer in South Bend Indiana. I wasn’t expecting much, but found myself disappointed that all the large displays (except one) were ‘replicas’. I’m not sure why I felt this way, since all fossils are ‘copies’. But ‘replica’ makes it seem fake.
edit: I think this is being misinterpreted. In my mind, all fossils are ‘copies’ of the original. The bone is gone, replaced by stone. But for some reason, calling something a replica doesn’t carry the same…majesty as the original copy. Maybe it’s just the thought that it could have been tampered with when making it out of plastic or fiberglass.
Most displays are likely to be replicas, I think. Few people would be interested in seeing a T. Rex hip bone in one display, half a triceratops horn in another, etc. Complete skeletons are a bit of a rarity so it would be tough to find all the parts of some species for all the different museums out there. Also, in order to build a complete display of a T. Rex or triceratops, you would likely use all replica parts because you would need to damage the fossils in order to connect them all together.
Finally, most of the actual fossils are valuable to researchers and putting them on display in museums would make them less available for study.