Dinosaur bones are mainly composed of calcium-based minerals such as hydroxyapatite. Under the intense conditions of metamorphism, these minerals would likely undergo chemical reactions and transform into different mineral assemblages characteristic of schist, such as micas, quartz, and feldspar.
Additionally, the extreme temperatures and pressures associated with metamorphism can cause the bone fragments to become fractured, distorted, or completely disintegrated. Over time, the original organic material of the bone would be broken down and replaced by minerals, leaving little to no trace of the original bone structure.
Therefore, the chances of finding a well-preserved dinosaur bone in metamorphic rock are exceptionally low. Most dinosaur fossils are found in sedimentary rocks, which are formed by the accumulation and compaction of sediments under less intense pressure and temperature conditions.