Abstract：
Saws are common tools used in postmortem dismemberment to alter human remains. Dismemberment may coincide with other concealment methods such as disposal in aquatic environments, so forensic anthropologists must recognize how taphonomy affects saw mark preservation. This study focuses on exposure of saw cut bone to a fluvial environment. Cross sections from pig humeri cut by a 7 TPI saw were evaluated on all cut surfaces for tooth hop (TH), exit chipping, and breakaway spurs. Pre-fluvial exposure, features were measured by two observers using a stereomicroscope while a one-dimensional profilometer was used to define surface roughness. Bones were randomly assigned to control or experimental groups and within each divided by duration of exposure (24, 48, 72, and 96 h). Control groups (four cross sections) were exposed to water in a 3-meter-long hydraulic channel; experimental groups (20 cross sections) were exposed to water and sediment in a 12-meter-long sediment-recirculating hydraulic channel. Velocity was maintained at 0.45 m/s. All measurements were repeated post-exposure. Observer A recorded 268 TH (mean: 3.70 ± 0.34 mm); post-exposure, count increased by 16.79% (mean: 3.71 ± 0.29 mm). Observer B recorded 247 TH (mean: 3.46 ± 0.42 mm); post-exposure, count decreased by 29.15% (mean: 3.36 ± 0.33 mm). All TPI estimates calculated include the 7 TPI saw. Exit chipping lost flakiness (in both channels), but was still visible. Breakaway spurs were not visibly altered. Surface staining was limited to bones exposed to sediment. Roughness was significantly lower in experimental groups post-fluvial exposure (W = 5705, p < 0.05). Overall, this fluvial environment did not obliterate saw mark evidence from bone.
摘要：
锯是用于死后肢解以改变人类遗骸的常用工具。肢解可能与其他隐藏方法相吻合，例如在水生环境中处置，所以法医人类学家必须认识到录音是如何影响锯痕保存的。这项研究的重点是将锯切的骨头暴露于河流环境中。在所有切割表面上评估用7TPI锯切割的猪肱骨的横截面是否有牙签（TH），出口缺口，和分离的马刺。河流前暴露，特征由两个观察者使用立体显微镜测量,而一维轮廓仪用于定义表面粗糙度。将骨骼随机分配到对照组或实验组，每组内按暴露时间（24、48、72和96小时）划分。对照组（四个横截面）在3米长的水力通道中暴露于水中；实验组（20个横截面）在12米长的沉积物再循环水力通道中暴露于水和沉积物。速度保持在0.45m/s。所有测量在暴露后重复。观察者A记录的TH为268（平均值：3.70±0.34mm）；曝光后，计数增加16.79％（平均：3.71±0.29mm）。观察者B记录247TH（平均值：3.46±0.42mm）；曝光后，计数减少29.15%(平均:3.36±0.33mm)。计算的所有TPI估计包括7个TPI锯。出口碎裂失去了片状(在两个通道中),但仍然可见。分离的马刺没有明显改变。表面染色仅限于暴露于沉积物的骨骼。河流暴露后实验组的粗糙度显着降低（W=5705，p<0.05）。总的来说,这种河流环境并没有消除骨骼中的锯痕证据。
