Final answer:
Burnt bones can shrink due to heat-induced distortion, but non-metric techniques remain useful for identification purposes. Unchanged bones or teeth must be differentiated from permineralized fossil bones, often through the analysis of cut marks indicative of perimortem trauma.
Step-by-step explanation:
When burnt, bone can undergo heat-induced distortion, which includes shrinkage and changes in its structure. However, experts in forensic or archaeological fields can still use non-metric techniques to assess and identify bone remains despite such alterations. In fact, the decrease in size of a structure is known as atrophy, which is typically associated with a reduction in size due to nonuse; whereas the changes in bone post-burning can be due to heat-induced distortion. Contrastingly, examining preserved bones or teeth, such as unaltered bones or shark teeth, requires differentiating them from permineralized fossil bones. One way to do this is through the observation of cut marks or injuries on the bone, such as those made by sharp objects like swords. These cuts reflect the energy and skill behind the blow and are indicative of perimortem trauma. They aid in distinguishing between bones affected by post-mortem changes versus those altered by permineralization over long periods.