CH.7: Processing, Resolving Commingling, and PReserving Remains

Principles of Skeletal Processing and Preparation

• Remains often arrive in the lab with remaining soft tissue and/or other adhered material

  • Obscure skeletal remains

• Processing

Processing

• Removal of soft tissue and other materials

• Allows for “direct visual analysis of the external bone surfaces” (p.183)

• Many approaches to processing

  • Remains should be documented (notes, photography, radiography) prior to and after processing

Prior to skeletal processing

• Mechanical removal (no tools)

• Dissection and Disarticulation

Mechanical removal

• No tools

• Significant soft tissue and/or adhering materials

Dissection and Disarticulation

• Use of sharp tools

• Take care to not scrape or nick bone

Skeletal Processing

• Maceration

• Carrion beetles

• Chemical approaches

Maceration

• Soaking in water, usually at various temperatures

  • Warm water is most common

  • Addition of detergents and de-greasing agents

• Time consuming, strong odor

Carrion Beetles

• Consume soft tissue

• Time consuming, decreases risk of compromising bone

Chemical approaches

• Bleaching, significant degreasing, etc.

• Risk integrity of bone and DNA yields

Skeletal Reconstruction

• Reassembling fragmented skeletal elements to allow better analyses and interpretations

  • Trauma, postmortem damage, etc.

• Reversible methods are preferred

  • Holding fragments together, tape/putty, reversible adhesive, etc.

• Matches should not be forced

• Often a time consuming and labor-intensive process

Commingling

• The “presence of more than one body or skeleton or the intermixing of body parts from more than one individual” (p.189)

• Mass graves, mass fatalities, etc.

Resolving Commingling

• Determining the number of individuals present

• Consideration of commingling should occur with every anthropological analysis

  • Even when it may be unlikely

• Perform skeletal inventory

  • Reconstruct if necessary

• Sort present elements by element and side

• Further sorting

• Minimum Number of Individuals (MNI)

• Most Likely Number of Individuals (MLNI)

Further sorting

• Pair-matching

• Articulation

• Osteometric sorting

• Taphonomy 

• DNA analysis

• X-ray fluorescence (XRF)

• Laser-induced breakdown spectroscopy (LIBS)

• Stable isotope analysis

• Consideration of biological indicators of age and sex, pathological conditions, etc.

Minimum Number of Individuals (MNI)

• Estimated after sorting

• Count “the number of repeated elements (or portion thereof)…and then taking the highest number” (p.192)

Most Likely Number of Individuals (MLNI)