I think He means that this beast's bones were very heavy and very strong. If this creature were very large, it would need big, strong bones. When we look at the bones of this Camerasaurus it is easy to think of brass beams and iron rods. I have heard people try to explain this verse by saying it is talking about a Hippopotomus. I have also heard it said that this is an alligator.
Someone is wrong.
I choose to believe the Bible. This does not answer all of the questions that we have about dinosaurs but it does raise some that scientist would have trouble answering. If we look at the evidence we can get the answers though. God wrote the Bible because He knows we like to find things out. I like to ask questions since this is the way I find things out.