skeleton
Enable an AI agent to recognise an anatomical skeleton, assess its completeness and structural condition, and determine which examination, handling or intervention is appropriate.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
Researched by: Codex + Grok
Purpose and description
Enable an AI agent to recognise an anatomical skeleton, assess its completeness and structural condition, and determine which examination, handling or intervention is appropriate.
A skeleton is an animal's rigid or pressurized supporting framework - typically an internal articulated endoskeleton of bone and cartilage in vertebrates, a cuticular exoskeleton in arthropods, or a fluid-filled hydrostatic skeleton in some soft-bodied taxa - that maintains shape, protects viscera, and transmits muscular force.
It can be Inventory skeletal elements and map fragments to anatomical regions with explicit uncertainty.; Compare represented elements and connections against an appropriate anatomical reference.; Assess proposed articulation or reconstruction without treating a plausible fit as established provenance.; Select examination or imaging methods suited to the material and living or specimen context.; Plan supported handling, movement or storage around identified weak elements and unstable connections.; Evaluate whether sampling, repair or clinical intervention is within the agent's authority and sufficiently supported by evidence..
Distinguishing features
Its elements can be interpreted as parts of an organism's internal anatomical supporting framework rather than an engineered frame.
A claimed whole skeleton should have anatomically interpretable element relationships; a pile of bones requires assessment before being treated as one individual's skeleton.
A partial skeleton must be identified as partial rather than implying that absent elements were absent during life.
Original skeletal material can be distinguished, or explicitly left unresolved, from casts, replacement elements and mounting hardware.
A shell or external supporting covering falls outside the provisional internal-framework scope and must be flagged for a registry boundary decision.
Scope
+ Whole skeletons and identifiable partial skeletal assemblages
+ Skeletal elements, their anatomical identities and their relationships
+ Completeness, articulation, alignment and structural continuity
+ Observed skeletal changes, damage, preservation and reconstruction
+ Constraints on examination, movement, sampling and intervention
- Whole-organism physiology, behaviour and general health
- Muscles, tendons and other soft tissues except where their attachments constrain skeletal interpretation
- Medical diagnoses or treatments requiring a separate clinical assessment
- Fossil-bearing rock, burial contexts and collection facilities as independently managed things
- Architectural frames, software skeletons and other metaphorical uses
- Replicas and digital skeletal representations as objects distinct from the anatomical material they depict
Characteristics
- Organism attribution
- Recorded taxon or organism group, identification basis and confidence; unknown allowed Determines which anatomical expectations can reasonably be used to assess identity and completeness.
- Biological and specimen context
- In a living organism; post-mortem in situ; recovered specimen; fossilised material; mixed or unresolved Changes what can be observed and which actions require clinical, collection or contextual controls.
- Skeletal material
- Bone; cartilage; mixed; mineral-replaced material; unresolved, recorded by element where necessary Supports recognition and selection of suitable examination and handling methods.
- Element representation
- Identified element counts and represented portions, with the anatomical reference and counting method stated Makes completeness assessable without treating fragments as complete elements.
- Individual association
- Element-to-individual attribution: supported; tentative; unassigned; conflicting Prevents a mixed assemblage from being interpreted as one coherent skeleton.
- Articulation and alignment
- Anatomically connected; disarticulated; reconstructed; displaced; unresolved, by connection Distinguishes observed anatomical relationships from those introduced during assembly.
- Element dimensions
- Millimetres or degrees, with named landmarks, method and uncertainty Supports comparison, fit assessment and detection of changes without relying on visual impressions alone.
- Structural condition
- Location-specific observations of continuity, cracking, fragmentation, deformation, surface loss and instability Identifies vulnerable regions and the evidence needed before movement or intervention.
- Introduced material
- Element-to-adhesive, support, implant or replacement relationship, with location and known purpose Separates anatomical material from additions that affect appearance, loading or interpretation.
Also called
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.skeleton
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 18 findings · 29 questions.
Skeletal identity Establishes what anatomical framework is represented and whether its elements belong together.
Completeness and condition cannot be interpreted reliably without an appropriate anatomical identity and individual association.
Anatomical attribution
Records the evidence for recognising skeletal material and attributing it to an organism group.
Framework identification
An evidence-qualified identification of the material as an internal skeleton or part of one.
- Which observable anatomical features support identifying this material as a skeleton or skeletal element? definition
- Which organism attribution is supported, by what reference or examination, and with what uncertainty? provenance
Individual association
Tests whether an assemblage represents one individual, several individuals or an unresolved mixture.
Element belonging
Records supported and disputed associations between elements and individuals.
- What recovery records, anatomical matches or other observations support assigning these elements to the same individual? provenance
- Do duplicate sided elements, incompatible sizes or conflicting context indicate that some elements must remain separately attributed? boundary
Anatomical coverage Describes which skeletal regions and elements are represented and how they connect.
A skeleton's identity depends on an anatomical arrangement, while missing or reconstructed portions limit what can be inferred.
Element inventory
Maps present, partial, unobserved and missing elements against a stated anatomical reference.
Represented anatomy
A region-by-region account of skeletal coverage without conflating absence with lack of observation.
- Which elements, sides and portions are identified, and which fragments remain unassigned? measurement
- For each expected but unrecorded element, is it demonstrably absent, inaccessible, unpreserved or simply not yet examined? boundary
Connections and orientation
Records anatomical connections, element orientation and the basis for any assembly.
Articulation evidence
Distinguishes preserved anatomical relationships from proposed or constructed arrangements.
- Which connections are observed in place, inferred from matching surfaces or imposed by reconstruction? provenance
- Which orientations or connections remain uncertain enough to prevent a confident reconstruction? boundary
Form and variation Records skeletal dimensions and developmental or anatomical variation relevant to interpretation.
Differences in skeletal form must be described before they are interpreted as damage, abnormality or mismatched elements.
Skeletal geometry
Captures comparable measurements of elements and their spatial relationships.
Landmarked dimensions
Measurements tied to identifiable anatomical landmarks and observation methods.
- Which lengths, angles or proportions matter for the intended comparison, and how are their landmarks defined? measurement
- How do missing portions, deformation or imaging limitations affect each reported measurement? measurement
Development and variation
Separates observed developmental features and anatomical differences from unsupported interpretations.
Variation assessment
Records features such as fusion, asymmetry and unusual element form with appropriate comparison limits.
- Which fusion states, asymmetries or unusual forms are directly observed, and which are obscured or reconstructed? measurement
- What suitable comparative evidence is needed before interpreting these features as developmental variation or a pathological change? boundary
Skeletal condition Assesses the integrity of skeletal material and distinguishes observations from explanations of change.
Local damage can compromise both physical stability and anatomical interpretation, while its timing and cause may remain uncertain.
Material integrity
Locates loss of continuity, surface deterioration and unstable skeletal regions.
Damage and stability
A localised account of defects and their implications for support or handling.
- Where are cracks, breaks, deformation, surface loss or unstable fragments present, and how extensive are they? measurement
- Which elements or connections need support or further assessment before loading, repositioning or handling? action
Change interpretation
Records evidence about when and how skeletal alterations arose.
Alteration history
Separates directly observed alterations from tentative accounts of biological change, post-mortem damage or preparation.
- What observations or records support attributing an alteration to change during life, post-mortem processes or later preparation? provenance
- Which competing explanations remain unresolved, and what examination could distinguish them? boundary
Examination and intervention Connects skeletal evidence and context to appropriate examination, handling and modification.
The same anatomical element requires different decisions when it is part of a living organism, a fragile specimen or a reconstructed display.
Access and handling
Determines how skeletal material can be examined or moved without unsupported assumptions about stability or access.
Examination plan
An examination and handling approach tied to the skeletal question and physical context.
- Is the skeleton within a living organism, exposed in situ or held as a specimen, and how does that constrain access? boundary
- Which examination method or supported movement can answer the current anatomical question, given the identified fragile regions and access constraints? action
Modification and sampling
Records the justification, authority and anatomical consequences of proposed changes.
Intervention decision
A reviewable decision about sampling, repair, mounting, reconstruction or referral for clinical intervention.
- Which skeletal element and portion would the proposed action alter, and what anatomical or future analytical evidence could it remove or obscure? action
- What consent, custodial authority or qualified assessment applies to this skeleton and the specific proposed intervention? action
- How will introduced supports, replacement elements or removed samples remain traceable to their original anatomical locations? provenance
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Kinds and varieties
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Bony vertebrate endoskeleton (osteichthyans and tetrapods, including the adult human skeleton of ~206 bones)
- Cartilaginous endoskeleton (chondrichthyans; also the embryonic/fetal vertebrate condition before ossification)
- Arthropod exoskeleton (chitinous cuticle, often mineralized; includes moulted exuviae as physical objects)
- Hydrostatic skeleton (fluid-filled cavity antagonized by body-wall muscle, as in cnidarians, nematodes, and many annelids)
- Axial skeleton (skull, vertebral column, ribs, sternum)
- Appendicular skeleton (limb girdles and free limbs or fins)
- Articulated museum or teaching skeleton (elements mounted in anatomical position, often with hardware)
- Disarticulated osteological assemblage (forensic, archaeological, or comparative collections of separate bones)
- Which of these kinds and varieties hold for the sense of skeleton this model covers, and on what evidence? provenance
Identifiers and schemes
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Wikidata - Q131626 - Item for anatomical/biological skeleton; confirm on Wikidata before treating as canonical in a registry row.
- MeSH - D012863 - Heading 'Skeleton' in the U.S. National Library of Medicine vocabulary.
- Foundational Model of Anatomy (FMA) - FMA:23881 - Skeletal system; individual bones have separate FMAIDs.
- UBERON - UBERON:0001434 - Multi-species 'skeletal system'; related class UBERON:0004288 is used for 'skeleton' in some imports - check the current ontology before binding.
- Terminologia Anatomica 2 - systema skeletale and named ossa - Latin and English official terms for the human skeletal system and its bones (FIPAT/IFAA).
- Which of these identifiers and schemes hold for the sense of skeleton this model covers, and on what evidence? provenance
Standards and regulation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Terminologia Anatomica 2 - FIPAT / International Federation of Associations of Anatomists (anatomical naming).
- Standards for Data Collection from Human Skeletal Remains (Buikstra & Ubelaker, 1994) - Arkansas Archeological Survey (recording protocol, not a statute).
- Human Tissue Act 2004 - United Kingdom (storage and public display of human skeletal remains).
- Native American Graves Protection and Repatriation Act (NAGPRA), 1990 - United States (Native American human remains, including skeletons, in federally connected collections).
- CITES (Convention on International Trade in Endangered Species) - UNEP/CITES Secretariat (cross-border trade in skeletal parts of listed species).
- ICOM Code of Ethics for Museums - International Council of Museums (provenance, display, and research on human and animal remains).
- Which of these standards and regulation hold for the sense of skeleton this model covers, and on what evidence? provenance
Real-world use
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Anatomy teaching: articulated plastic or real-bone skeletons in medical, veterinary, and art studios.
- Clinical medicine and radiology: living skeletal system as the reference for fracture, dysplasia, and bone-density work.
- Forensic anthropology: identification, trauma timing, and biological profile from recovered human bones.
- Bioarchaeology and museum osteology: excavated or curated human and animal skeletons as documented specimens.
- Comparative zoology and palaeontology: mounted or boxed skeletons (and fossil skeletons) used to study locomotion and phylogeny.
- Wildlife and customs enforcement: seized ivory, horn, bone, and whole skeletons as CITES specimens.
- Which of these real-world use hold for the sense of skeleton this model covers, and on what evidence? provenance
Typical measurements
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Element count (adult human) - 206 canonical; about 200-213 with sesamoids, cervical ribs, and sacral-fusion variants - count
- Dry mass of a prepared adult human skeleton - approximately 4-12 - kg
- Maximum femoral length (adult human, osteometric) - about 320-520 - mm
- Reconstructed living stature from long bones (adult human) - about 140-200 - cm
- Areal bone mineral density (DXA, adult lumbar spine) - about 0.7-1.3 - g/cm²
- Assemblage completeness (archaeological/forensic inventory) - 0-100 of expected elements - %
- Which of these typical measurements hold for the sense of skeleton this model covers, and on what evidence? provenance
Failure modes and hazards
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Fracture, non-union, and pathological bone loss (osteoporosis, osteomyelitis, neoplasia) in the living skeleton.
- Taphonomic destruction after death: acidic soil, scavenging, weathering, and excavation breakage.
- Commingling and misassociation of elements from more than one individual.
- Loss of provenience or illegal trade, especially of human remains and CITES-listed taxa.
- Hardware failure or incorrect rearticulation in mounted teaching skeletons, producing false joint relationships.
- Infection and chemical hazards from historical wet preparations (formalin, arsenic, residual tissue); ethical harm from unconsented display of human skeletons.
- Which of these failure modes and hazards hold for the sense of skeleton this model covers, and on what evidence? provenance
Regional variation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Legal control of human skeletons differs sharply: NAGPRA in the United States, the Human Tissue Act in the United Kingdom, and other heritage or religious rules elsewhere; some jurisdictions effectively prohibit research retention.
- The word 'skeleton' in construction English often means a steel building frame, not an anatomical object.
- Comparative biologists treat exoskeleton and hydrostatic skeleton as full kinds; clinical anatomy usually means only the vertebrate endoskeleton.
- Adult bone-count conventions and named variants (sesamoids, Wormian bones) differ slightly across textbooks and populations.
- Museum practice ranges from fully articulated public mounts to boxed, disarticulated research series; display of human remains is restricted or refused in many countries.
- Which of these regional variation hold for the sense of skeleton this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Skeletal system (living) - The living system includes marrow, periosteum, cartilage, ligaments, and blood supply; a prepared skeleton is the defleshed mineral framework only.
- Individual bone (os) - A bone is one element; a skeleton is the organized set of elements of one organism (or a mount presented as such).
- Skull - The skull is the cranial and mandibular subset of the axial skeleton, not the whole framework.
- Cadaver / anatomical donor - A cadaver retains soft tissue; a skeleton has been reduced to bone (and sometimes cartilage or ligaments).
- Fossil (permineralized remains) - A fossil skeleton has had original tissue replaced or infilled by mineral; a recent skeleton retains collagenous bone histology.
- Anatomical replica or cast - Plastic or plaster teaching models copy form but lack bone histology, DNA, and legal status as human tissue.
- Structural frame / armature (building, vehicle, sculpture) - An engineered load path of steel, timber, or wire; not an organism's tissues. Separate by material and whether it belonged to an animal body.
- Mollusc shell - A shell is an external calcium-carbonate exoskeleton of a different developmental origin; arthropod cuticle and vertebrate bone are not shells.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of skeleton this model covers, and on what evidence? provenance
Sources
- Gray's Anatomy: The Anatomical Basis of Clinical Practice - Standard clinical description of the human skeletal system, axial/appendicular division, bone counts, and functional roles of support, protection, and leverage.
- Terminologia Anatomica, 2nd edition (TA2) - International anatomical nomenclature for the skeletal system and named bones issued by FIPAT/IFAA.
- The Human Bone Manual - Practical osteology: element identification, adult vs juvenile skeletons, measurements used in bioarchaeology and forensic anthropology, taphonomy and completeness.
- Standards for Data Collection from Human Skeletal Remains - Widely used recording protocol for archaeological human skeletons (inventory, age, sex, metrics, pathology).
- Skeleton - Overview of endoskeleton, exoskeleton, and hydrostatic skeleton as the three mechanical types distinguished in comparative biology.
What the second pass must settle
- Does vr.tr.skeleton include exoskeletons and other biological supporting systems, or only internal frameworks of bone and cartilage?
- Does the registry treat an isolated bone as a partial skeleton or assign it to a neighbouring skeletal-element model?
- Which anatomical references and developmental stages should define expected element coverage for each supported organism group?
- How should fossil replacement, mixed original and replica assemblies, and extensively reconstructed specimens affect classification as a skeleton?
- Which context-specific standards should govern condition assessment and intervention for living organisms, human remains and nonhuman specimens?