Final answer:
Unaltered bones retain original organic composition while permineralized fossil bones are mineral-filled and stone-like. Living bones are dynamic, containing living cells and a bone matrix with collagen and calcium crystals.
Step-by-step explanation:
To distinguish unaltered bones or shark teeth from permineralized fossil bones, it is necessary to understand their preservation processes and structures. Unaltered bones, such as those you might find in a recent archaeological context, have not undergone significant chemical change and retain much of their original organic composition, including collagen and other proteins. In contrast, permineralized fossils are those in which the spaces within the bone have been filled with minerals from groundwater, effectively turning the bone to stone, while also preserving its original structure.
Living bones are very different from their preserved counterparts. They are dynamic, strong, flexible, and involved in numerous metabolic processes. This distinction from fossilized bones is evident through the presence of living cells, blood vessels, and nerves within the bone matrix, which consists of protein fibers, mainly collagen, mineralized with calcium crystals.
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