<It says in PDW that predators have denser (not thicker) bones that also fossilize better because they need to fight more and are in greater danger of nonlethal injuries that they wouldn't survive if their bones would break.>
The first reference I could find on this is:
Could T. rex swim?
By the way, thick and dense are near synonyms, though dense does carry more connotation of tightly packed, while thick's connotation is more like a lot of something. Because the question concerned how dense the bones are, I used thick to avoid implying the answer to my own question.
Interesting that HP Andy Farke raised a similar question early this month, though he did request off-list answers.