Reading Bone Surface Marks — Trampling, Teeth, Cuts, Weathering

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Quick field triage vs what to record for later analysis

Field quick‑ID

Fast visual cues you can use in the field

Look first at edge geometry, repeatability, and context. V‑shaped, fine parallel striae that repeat and occur near joint surfaces point to sharp tools; rounded pits, crushes and broken ends suggest tooth loading or trampling. Record before removal.

  • Edge shape: V vs rounded vs chipped
  • Pattern: solitary pits vs repetitive striae
  • Context: associated fractures, nearby teeth, bedding orientation
What to record

Minimum documentation for later lab work

Photograph multiple angles with a scale and north/orientation; note microhabitat, position in situ, associated specimens, and any adherent matrix. Sketch cross‑section appearance and list any co‑occurring marks on the same bone.

  • Photographs: overall, detail at scale, cross‑section sketch
  • Context notes: bedding, association, probable trampling surface
  • Handling: stabilise but avoid aggressive cleaning — record original surface
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Quick decision table — six visual checks

Agent Edge shape Cross‑section hint Spacing / pattern Associated fractures Polish, striae Contextual clue
Trampling Rounded, crushed margins Broad, flattened chips Irregular; isolated pits and micro‑chipping Fragmentation with abraded ends Possible smoothing/polish from movement High energy surface, mixed orientations
Carnivore tooth marks Pits and punctures; bisected pits Crushing and cone‑fracture profiles Paired tooth scores, aligned pits Perimortem fractures from biting Occasional striations across pits Associated with tooth fragments and gnawing patterns
Human cut marks Sharp, clean V‑shaped incisions Fine, linear cross‑section with burrs Regular, clustered, directional May co-occur with disarticulation cuts Distinct parallel striations Located near muscle attachments or joints
Weathering Flaky, exfoliating surfaces; longitudinal cracks Surface lamella separation Non‑repeating, patchy surface loss Surface‑supraficial cracks; brittle flakes Matte, chalky surfaces rather than polished Exposure to sunlight, dry cycles; root association possible
Root etching Meandering narrow grooves Shallow rounded incisions Irregular, winding Little associated fragmentation Localized fine etching, sometimes with organic film Contact with roots, soil organic matter visible

Use this table as a rapid checklist. A single attribute rarely proves an agent; combine several observations and context.

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Central visual triage workflow — stepwise decision path

Follow these ordered observations before any invasive action. Each step reduces ambiguity; stop and document when uncertain.

  1. Observe edge geometry at low magnification. Use a hand lens or loupe: are edges sharp and V‑shaped, or rounded and compressed? Sharp parallel incisions with micro‑striations suggest a lithic or metal blade; rounded, crushed edges suggest compressive forces (trampling or biting).
  2. Check cross‑section profile. Sketch or photograph a broken edge to show whether the mark has a V‑shaped groove, U‑shaped pit, or flattened chip. V grooves often align with cutting, U or conical shapes with puncture/pit events.
  3. Map pattern repeatability. Note spacing, orientation, and clustering. Repeated, parallel shallow striae typically indicate cutting; paired deep scores or aligned pits point at dentition; random isolated pits and abrasion point to trampling or transport.
  4. Compare fracture context. Are fractures perimortem (fresh, with hinge fractures, sharp edges) or post‑burial and brittle? Bite‑induced fractures commonly radiate from pits; trampling produces comminuted surfaces and abraded ends.
  5. Search for secondary traces. Polishing, striation sets, embedded plant or root traces, and adhered matrix give clues: polish with directional microstriations supports rubbing/contact movement while chalky exfoliation suggests weathering.
  6. Decide provisional attribution or escalate. If multiple features point to the same agent, record a provisional attribution (e.g., “probable carnivore tooth marks”) and collect standardized photos and notes. If conflicting signals remain, flag the specimen for micrography or specialist review.

Ambiguity example: a shallow V‑groove with surrounding abrasion may represent a cut subsequently abraded by trampling. In such cases, document both interpretations, prioritise non‑destructive imaging, and avoid aggressive cleaning that removes surface evidence.

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Diagnostic signatures — concise agent bands

Trampling — typical signature

Crushing and abrasion with irregular pits and rounded margins. Damage often occurs across multiple bones in a dispersal area and shows varied orientations.

Rounded crushed edges
Isolated pits and micro‑chipping
Surface smoothing / polish from sediment movement

Common confounders: small carnivore gnawing can mimic pits — check for paired tooth scores or embedded enamel fragments.

Carnivore tooth marks — typical signature

Pits, punctures and scores with evidence of crushing and radiating fractures. Look for paired marks from opposing teeth and concentrated gnawing near epiphyses.

Conical pits with crushed margins
Paired scores or aligned pits
Perimortem bite fractures and bone spall

Common confounders: trampling can round pit edges; examine pattern geometry and associated fractures.

Human cut marks — typical signature

Sharp, narrow, often parallel incisions located at muscle attachment sites or along joint surfaces. Micro‑striations and regular orientation are strong indicators.

V‑shaped incisions with burrs
Parallel clusters with consistent orientation
Location consistent with disarticulation or defleshing

Common confounders: root etching may produce narrow grooves — check striae pattern and context.

Weathering — typical signature

Surface flaking, cracking, and peeling, often aligned with long axis and showing brittle loss. Surfaces feel chalky or fibrous rather than polished.

Longitudinal cracks and flaking
Surface lamella separation
Patchy, non-repeating loss of cortical surface

Common confounders: post‑depositional chemical etching may resemble weathering; check microtexture under magnification.

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Field documentation mini‑checklist

Photographs
Overall context, scale, orthogonal detail shots.
Scale & orientation
Include a scale and indicate “up” / bedding direction.
Sketch cross‑sections
Draw perceived profile of marks before cleaning.
Associated material
Note nearby tooth fragments, tools, or plant matter.
Handling notes
Stabilize; avoid scraping original surfaces.
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Field‑note prompt and suggested references

Choose one specimen in your current collection and record a focused diagnostic note using the workflow above. Label it with a schematic identifier (for example BOX-A / SAMPLE-CODE), take a minimum of three photographs at different scales, and write a provisional attribution plus the primary reasons for that choice.

Suggested reference types (for follow‑up reading): field manuals on bone taphonomy, descriptive keys for surface‑modification morphology, and museum preparator guidelines on non‑destructive documentation. Seek peer consultation when attributions will inform broader ecological or archaeological interpretation.