Final answer:
When examining bone preservation, paleontologists look for mineral composition, original biological material, and changes in density and durability to distinguish permineralized fossils from unaltered bones. Fluids involved in preservation and strength and flexibility under various conditions are also evaluated to determine the preservation method.
Step-by-step explanation:
Examining Bone Preservation
When examining the preservation of a bone, paleontologists look for several features to identify the preservation method. Permineralization is a common form of bone preservation where minerals like quartz, calcite, or pyrite permeate the bone's pore space and crystallize. To distinguish permineralized bones from unaltered bones or shark teeth, one would inspect the mineral composition, look for changes in density and durability, and look for signs of original biological material. In unaltered preservation, bones or teeth are preserved with little or no change, maintaining their original structure. On the other hand, permineralized bones are denser due to the mineral infusion.
When determining the mode of preservation, factors like the presence of soft or hard parts, altered or unaltered condition, and the presence of trace fossils should be considered. Additionally, the role of fluids in the preservation is crucial, looking at the sedimentary environment that may have accounted for the oxygen-free conditions necessary for quick burial and preservation.
Finally, the flexibility and strength of the bone can also be evaluated under different conditions, which may indicate the preservation process it has undergone. A permineralized bone would typically be denser and therefore stronger, but potentially less flexible than an unaltered bone.