15.1: Articulating MNI in the Cranium
- Page ID
- 138561
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Example of activity to represent cranial articulations
Supplies Needed
- Decks of cards labelled with skull bones (directions and template provided)
- Pipe cleaners
- Optional: Cranial pictures, online 3D model of a skull, or a cast of a skull (e.g. magnetic osteological teaching skull)
Readings
- Organ, Jason and Jessica Byram. 2019. Appendix A: Osteology. Explorations.
Introduction
Preparation of Card Decks
- Make a variety of color coded card decks (see photo below for examples). Each color deck represents a single complete skull. The colors are a symbolic way to represent actual skeletal differences, such as differences in body size, coloration, osteological age, and preservation. To make this a little more challenging, be sure to make multiple complete skull decks in the same color (i.e., three full decks of blue). This allows students to make MNI interpretations based not only on color (easy-level), but also on duplicate elements (more challenging and more realistic).
- Within each color deck/individual skull, you will label cards with the terms below (see the template at the end of this document). Punch holes into each card to represent the total number of articulations that the bone should have (number of holes per card indicated in brackets next to the bone label).
- Left parietal (5)
- Right parietal (5)
- Left temporal (4)
- Right temporal (4)
- Left zygomatic (4)
- Right zygomatic (4)
- Left maxilla (4)
- Right maxilla (4)
- Ethmoid (4)
- Sphenoid (9)
- Frontal (8)
- Occipital (5)
Color coded decks can be coded using different imagery, card stock, etc. Note different numbers and patterns of punched holes.
Steps
- Prior to the activity, shuffle all the decks of cards together, mixing up the multiple individuals.
- Distribute stacks of shuffled cards to groups or individuals around the class.
- First, have the students work to establish MNI.
- This is most easily achieved by first sorting the decks by color, and next looking for duplicates within and between the colors. If, for example, there are two blue, one orange, and one green ethmoid, the MNI would be four.
- Once the groups have established their MNI, have a group discussion about their experiences and challenges. Relate this schematic exercise to practical MNI estimation on actual archaeological assemblages.
- It is worth addressing at this point how the color coded cards oversimplify variation; discuss with the class the types of variation we might be looking for in actual archaeological assemblages (e.g. growth and development differences, body size differences, taphonomic differences).
- Also discuss preservation: You have dealt complete skulls, what happens if only part of an element is present?
- Have the students trade cards to make complete decks for each individual. The next stage will involve refitting the skull bones to learn their complex articulations.
- Distribute pipe-cleaners to the students. Have the students use the pipe cleaners to connect the elements that would articulate in real life. Note: Students may find this easier if they keep the pipe cleaners longer with looser articulations rather than trying to create a 3D model (see photos below).
- Instruct students to identify and name each suture as it has been stylized in their cranial-spider-sculpture. They should try to first refit bones and name sutures unaided, but after attempting this, they may compare their schematic sculpture to cranial pictures (or an online 3D model) of a human skull.
Review Questions
- Discuss your experiences with this activity. What did you learn?
- What challenges did you have with this activity?
- Would these challenges be similar with actual osteological assemblages? What additional challenges might be present? Discuss the types of variation that might be present including growth and development differences, body size differences, and taphonomic differences. Also be sure to discuss preservation and what happens if only part of an element is present.
Adapting for Online Learning
For Further Exploration
References
Image Attributions
Template for the card decks by Rebecca Gilmour original to Explorations Lab and Activities Manual is under a CC BY-NC 4.0 License.
Articulating MNI in the Cranium: Worksheet
Establish the Minimum Number of Individuals (MNI)
Spider-Skull: Refitting the Articulations:
- Left parietal
- Right parietal
- Left temporal
- Right temporal
- Left zygomatic
- Right zygomatic
- Left maxilla
- Right maxilla
- Ethmoid
- Sphenoid
- Frontal
- Occipital