Chapter 1: Building Taxonomy‑Based Libraries

Created by Sarah Choi (prompt writer using ChatGPT)

Building Taxonomy‑Based Libraries (Skeletons, Skins, Gaits)

Reference, Research & Visual Libraries for Creature Concept Artists

As a creature concept artist, you’re not just drawing monsters or animals—you’re quietly building a private museum in your head. Every skeleton you study, every pelt or scale pattern you notice, every weird walk cycle you observe in a zoo or nature doc becomes part of a rich taxonomy‑based visual library you can draw on in production.

This article walks you through how to deliberately build that library using the logic of biology: taxonomy (how living things are grouped), anatomy (skeletons and soft tissue), and behavior (gaits and movement). We’ll frame everything in ways that are usable both for concept‑side creature artists (ideation, exploration, key art) and production‑side creature artists (model sheets, orthos, callouts, handoff to downstream teams). Along the way, we’ll emphasize field sketching, museums, scans, and ethics so your reference practices are both powerful and respectful.

1. Why Taxonomy Matters for Creature Design

Most artists start by thinking in silhouettes and vibes: “big herbivore,” “sleek apex predator,” “spidery cave thing.” Taxonomy adds a deeper layer of structure by asking: “What real‑world clades and families does this belong to?” Even if your creature is fantastical, the mental anchors of taxonomy make it more convincing.

1.1 From Vibes to Lineages

Instead of only “wolf‑like” or “reptilian,” you start asking questions like:

  • Is this more canid (dogs, wolves, foxes) or felid (cats, panthers, lynx)?
  • Does it move more like an ungulate (deer, horses, antelope) or a cursorial predator (cheetah, greyhound)?
  • Is its body plan closer to saurischian dinosaur, crocodilian, or monitor lizard?

Each of these lineages carries patterns: skull shape, limb proportion, tail usage, gait types. That means your visual library becomes organized by families and clades, not just aesthetic mood boards. You can mix and match lineages to create hybrids, but you know what you’re breaking and why.

1.2 How Taxonomy Helps Both Concept and Production

  • Concept‑side benefits
    • Faster ideation: you can quickly say, “Let’s combine a mustelid spine with a capybara skull and ostrich legs,” because you know what those are.
    • Clear pitch language: you can communicate with art directors using real animal hooks (“this boss is a theropod–bat chimera with deep‑sea fish teeth”).
  • Production‑side benefits
    • Consistency: having a taxonomy‑based reference pool means the whole team keeps a creature family visually coherent across variants and LODs.
    • Reuse: once a “raptor‑lineage” skeleton library is built, it can inform multiple creatures, mounts, NPCs, and background fauna.

2. Structuring Your Taxonomy‑Based Library

A taxonomy library should be searchable, expandable, and cross‑linked between skeletons, skins, and gaits. Think of it less as a random Pinterest board and more like a personal database.

2.1 Core Axes: Skeletons, Skins, Gaits

Organize your library along three primary lenses:

  1. Skeletons (Structure)
    • Skull shape, jaw hinges, dentition
    • Limb count and arrangement (biped, quadruped, hexapod)
    • Joint types and ranges (ball‑and‑socket vs hinge)
    • Spine flexibility, tail construction
  2. Skins (Surfaces)
    • Fur length, clumping patterns, color zoning
    • Scale size, overlap directions, plating vs soft regions
    • Feathers (contour vs down, wing coverts, tail fans)
    • Skin folds, calluses, keratin structures (horns, beaks, claws)
  3. Gaits (Movement)
    • Walk, trot, canter, gallop for quadrupeds
    • Hopping, bounding, climbing gaits
    • Flight strokes (flapping, soaring) and swim strokes (undulation, paddling)

Every time you add a new reference (photo, sketch, screenshot, scan), try to tag it with at least one taxonomy term and one of these axes.

2.2 Simple Folder & Tagging Structure

You don’t need fancy software; consistency is the key. For instance:

  • Folders:
    • Animals/Mammals/Carnivora/Canidae/Skeletons
    • Animals/Birds/Raptors/Feathers_WingPlans
    • Animals/Reptiles/Crocodilia/Gaits
    • HybridStudies/Fantasy/Griffin_SkeletonNotes
  • Tags:
    • skeleton, skull_profile, hind_limb, plantigrade, digitigrade
    • fur_long, feather_fan, osteoderm, scale_large
    • gallop, bound, hover, undulation, brachiate

For production artists, having shared naming and tagging across the team allows:

  • Cross‑project reuse of rig notes and gait sheets.
  • Faster onboarding (“here’s our quadruped skeleton pack and biped gait library”).

3. Skeleton Libraries: Building from the Inside Out

Skeletons are your structural blueprints. Even if you stylize heavily, understanding bone logic helps you avoid impossible joints and weight‑bearing errors.

3.1 Key Skeletal Archetypes to Collect

Prioritize collecting references and sketches of these archetypes:

  • Cursorial mammals (built for running)
    • Examples: horse, deer, antelope, cheetah, greyhound.
    • Visual traits: long distal limbs, reduced toes, lightweight skulls, springy spines.
  • Power‑focused predators
    • Examples: lions, tigers, bears, big dogs, crocodiles.
    • Visual traits: heavy shoulder girdles, robust necks, powerful jaws.
  • Diggers and burrowers
    • Examples: badgers, moles, armadillos, wombats.
    • Visual traits: massive forelimb bones, wide claws, reinforced shoulder blades.
  • Climbers and brachiators
    • Examples: primates, sloths, some marsupials.
    • Visual traits: mobile shoulder joints, long arms, hook‑like hands or claws.
  • Aquatic and semi‑aquatic vertebrates
    • Examples: dolphins, seals, crocodiles, penguins, fish families.
    • Visual traits: streamlined vertebrae, flipper modifications, reduced hind limbs in some lineages.
  • Avians and flight‑adapted reptiles
    • Examples: eagles, owls, bats, pterosaurs (fossil reconstructions).
    • Visual traits: lightweight bones, keel on sternum, fused vertebrae, wing finger elongations (bats, pterosaurs).

Collect both full skeletons and close‑ups of critical joints: shoulders, hips, ankles, wrists, neck base, tail base.

3.2 Field Sketching Skeletons in Museums

Museums are treasure troves for skeleton libraries.

  • Before you go
    • Make a rough shot list: “quadruped hip joints, various skulls in profile, bird shoulder structure.”
    • Bring a sketchbook, a soft pencil, and your phone for reference photos (if allowed).
  • On site
    • Start with big simple masses: rib cage, pelvis, skull, major limb bones.
    • Note the center of mass—often around the shoulders in quadrupeds, or hips in bipeds.
    • Draw the joint axes as simple lines or arrows: where can it bend, and in which plane?
  • Afterwards
    • Annotate your sketches at home: write labels like “digitigrade,” “fused radius/ulna,” “long cervical vertebrae.”
    • File your photos into your skeleton folders and tag them: museum_skeleton, hip_joint, avian_pectoral_girdle.

For production artists, you can transform field sketches into:

  • Skeleton overlays for turnarounds.
  • Quick rigging guides showing joint limits.
  • Internal structure callouts on model sheets.

3.3 Scans & 3D Skeletons (and Ethics)

3D scans of skeletons (from online repositories or studio scans) can be invaluable:

  • Rotate skeletons to understand volume in 3D.
  • Screenshot multiple angles for orthos and callout sheets.

However, always:

  • Check the license (Creative Commons, educational access, commercial use, etc.).
  • Credit the source in internal documentation where appropriate.
  • Avoid redistributing raw scan files if the license forbids it. Instead, point teammates to the original source.

4. Skin Libraries: Surfaces, Coverings, and Materials

Once you understand the internal structure, you can layer on skins: fur, scales, feathers, exoskeletons, and bare skin. As a creature artist, you’re effectively building a material library for living things.

4.1 Classifying Surfaces by Function

Don’t just collect “cool textures.” Think in terms of function and placement:

  • Thermal control
    • Thick fur on torso, thinner fur on limbs.
    • Heat dump zones: inner legs, neck, ears with sparse fur.
  • Protection & armor
    • Scales or osteoderms over vital organs.
    • Horn sheaths, keratin plates, thickened knee pads.
  • Display & communication
    • Bright plumage on chest, tail fans, crests, dewlaps.
    • Color patterns that align with muscles (stripes along limbs, spots on flanks).
  • Camouflage & environment
    • Counter‑shading (lighter belly, darker back).
    • Muddy tones for marsh animals, bluish for deep sea, sandy for deserts.

In your library, pair:

  • Photos or sketches of the surface.
  • Short notes: “thick guard hairs,” “velvety short fur,” “matte scale plates with gloss in joints.”

4.2 Field Sketching Skins & Patterns

In zoos, aquariums, farms, parks, or even with pets:

  • Zoom in: draw a small patch of fur direction on the shoulder, noting growth direction and clumping.
  • Observe transition zones: where feathered parts meet bare skin; where scales end and soft tissue begins.
  • Note wear patterns: scuffed fur around collars, bald patches, chipped claws, dulled horn tips.

For concept artists:

  • These studies help you design believable creature materials for key art and marketing illustrations.

For production artists:

  • They translate into material callouts, tiling texture references, and groom direction guides for Character/Creature Art and Groom teams.

4.3 Building a Scan‑Aware Surface Library

Studios may use:

  • Photogrammetry of pelts, feathers, or scales.
  • High‑res material scans (for normals, roughness, albedo).

As a concept artist collaborating with scan teams:

  • Attach clear reference boards showing the desired fur length, direction, and color breakup.
  • Indicate what should be scan‑based vs hand‑painted (e.g., facial markings better painted to match expressions; large flat scales good for scanning).

Ethically:

  • Verify that scanned samples (pelts, skins, feathers) are sourced legally and ethically.
  • Avoid glamorizing illegal wildlife trade (e.g., tiger pelts, illegal ivory) in your documentation. If you reference them for learning, contextualize with conservation awareness.

5. Gait Libraries: Walks, Runs, and Everything in Between

Gaits are how your skeletons and skins move. A gait library is essentially a collection of motion archetypes you can reuse across many creatures.

5.1 Gait Types to Capture

Focus on:

  • Quadruped gaits
    • Walk, trot, canter, gallop. Note footfall patterns: which foot lands first, how many feet are on the ground at once.
  • Biped gaits
    • Walks and runs with varying postures (upright vs hunched).
    • Loping, skulking, strutting.
  • Specialized gaits
    • Bounding (weasels, ferrets, some predators closing distance).
    • Hopping (kangaroos, rabbits).
    • Brachiation (apes swinging).
    • Crawling and slithering (snakes, lizards, larvae).
    • Flight strokes (downstroke, upstroke, gliding transitions).
    • Swimming (undulation in fish, paddling in dogs, flipper strokes in seals).

Tag each gait reference with:

  • species, gait_type (walk, trot, etc.), tempo (slow/medium/fast), terrain (rocky, water, air).

5.2 Field Sketching and Video Studies

You can build a strong gait library with live observation + video analysis:

  • At zoos or parks:
    • Do quick gesture sketches focusing only on center of mass and footfalls.
    • Don’t chase detail; draw the same animal over and over in 10–30 second bursts.
  • From video:
    • Scrub frame by frame to capture key poses for a walk cycle or jump.
    • Draw small thumbnails of each key pose, then arrows indicating the sequence.

These studies are useful for:

  • Concept artists sketching dynamic action poses and key art.
  • Production artists making gait sheets for Animation and Rigging: side view breakdowns of cycles, with notes like “hip rotation exaggerated here,” “spine flex peaks here.”

5.3 Integrating Gait Libraries into Pipelines

  • For a new creature:
    • Start by picking a base gait archetype from your library (e.g., “wolf‑like trot + kangaroo bound hybrid”).
    • Share 1–2 real animal videos or studies in the brief for Animators.
  • For families of creatures:
    • Use taxonomy: all members of a certain family can share a base gait, then you layer stylization (heavier armor, longer tails, etc.).
    • This keeps the world cohesive—players subconsciously recognize related species by how they move.

6. Field Sketching: Ethics, Safety, and Good Habits

Field sketching is one of the most powerful tools for building your taxonomy‑based library—but it comes with responsibilities.

6.1 Basic Field Etiquette

  • Respect the animals
    • Don’t taunt or provoke animals to get “more interesting” poses.
    • Observe posted rules about distance and flash photography.
  • Respect the space
    • Follow zoo, park, or sanctuary guidelines about where you can sit, stand, or linger.
    • Don’t block other visitors or staff.
  • Respect the staff
    • If you’re unsure about rules, ask politely.
    • If staff ask you not to draw or take photos in specific areas, comply.

6.2 Drawing Without Exploitation

Some animal venues—like unethical roadside zoos or exploitative marine shows—prioritize profit over animal welfare. As an artist, you can:

  • Prefer accredited zoos, aquariums, and sanctuaries with clear welfare standards.
  • If you learn a venue is harmful, reconsider using it as a reference source or at least contextualize studies with awareness (“I drew this orca here, but this captivity situation is harmful; wild footage is better reference”).

Your visual library doesn’t exist in a vacuum; it reflects how you value living creatures.

7. Museums, Fossils, and Deep Time Libraries

Museums and fossil collections are your gateway to extinct lineages and speculative evolution.

7.1 Museum Ethics and Permissions

Most museums welcome sketching, but:

  • Check their photo and sketching policies—some areas may restrict photography.
  • If you plan to publish work directly based on their displays (for a paid art book, online course, etc.), it’s courteous and sometimes necessary to:
    • Review their image use guidelines.
    • Ask permissions for direct reproductions of specific displays.

Give credit when you reference specific reconstructions or illustrations, especially those built by paleoartists.

7.2 Building Deep‑Time Taxonomy Libraries

Organize extinct creatures in your library similarly to living ones:

  • Fossils/Theropods/Skeletons
  • Fossils/Plesiosaurs/Flipper_Studies
  • Fossils/Mammalian_Megafauna/Skulls

Annotate:

  • “Speculative soft tissue; multiple reconstructions disagree.”
  • “Tail posture contested; check alternative sources.”

For creature design, this transparency helps you choose whether to lean into a classic look or riff on emerging science.

8. Scans, Photogrammetry, and Digital Ethics

Digital tools make it easy to hoard reference. They also make it easy to accidentally cross ethical lines.

8.1 Using Online Photos and Videos

When collecting screenshots or images from online sources:

  • Credit the source in your internal notes: photographer name, institution, channel.
  • Avoid redistributing images that are clearly watermarked or behind paywalls. Instead, keep them in your private reference pool.

For public work (art books, tutorials, portfolio breakdowns):

  • Use images you have the rights to: your own photos, licensed stock, or public domain resources.
  • If you must show another creator’s work to explain your process, keep usage minimal and attribute clearly.

8.2 Scan & Photogrammetry Rights

If your studio or team captures scans of taxidermy mounts, skeletons, or live animals:

  • Clarify ownership and permitted use: studio‑only, project‑only, or broader internal asset library?
  • Store scans securely with clear metadata: source, date, location, and any restrictions.

Avoid sharing proprietary scans externally without explicit permission, even if “everyone does it.” As production‑side artists, you’re often gatekeepers of sensitive reference.

9. Making Taxonomy Work in Real Pipelines

A taxonomy‑based library is only useful if it’s actually used. Here’s how both concept‑side and production‑side creature artists can plug it into daily work.

9.1 For Concept‑Side Creature Artists

When you receive a brief:

  1. Identify the taxonomic anchors
    • “Forest guardian spirit, quadruped with antlers” → likely ungulate base with cervid skull cues.
    • “Aquatic cave predator” → mix of cave fish + crocodilian + eel.
  2. Pull relevant library boards
    • Skeleton: deer skull, horse limb mechanics.
    • Skin: mossy fur, algae patches, bark‑like plating.
    • Gait: slow regal walk, sudden bounding charge.
  3. Design within lineages first, then break rules
    • Start with believable structures.
    • Add new traits (extra limbs, glowing organs, anti‑gravity fins) as deliberate design choices, not randomness.
  4. Document your references in your handoff
    • Include a small strip of photos/sketches with notes: “based on elk skull + horse spine; gait like a moose in shallow water.”

9.2 For Production‑Side Creature Artists

As you refine and lock in designs:

  • Maintain shared taxonomy boards per creature family:
    • “Raptor‑line family references,” “Drake family skeletons,” “Burrower class gaits.”
  • Build standardized model sheets:
    • Front/side/back orthos with subtle skeletal overlays.
    • Callouts showing skin materials and transitions (scale → fur → horn).
    • Gait strips: 6–8 key poses for main locomotion modes.
  • Communicate with Rigging & Animation:
    • Provide rig notes informed by skeleton logic: “shoulder blade slides over ribcage here,” “tail base supports most rotation.”
    • Share gait references for each state (idle, walk, run, attack).
  • For variants and LODs:
    • Use taxonomy to keep shapes coherent: a “juvenile” variant keeps core skeletal proportions but with changes in skull ratio and limb length, not arbitrary shrinkage.

10. Keeping Your Library Alive

A taxonomy‑based visual library is a living system—just like the organisms it represents.

10.1 Regular Maintenance Rituals

  • Weekly
    • Add new sketches and photos from any field trips or study sessions.
    • Tag at least a few older images you skipped earlier.
  • Monthly
    • Pick a lineage (e.g., “mustelids” or “raptors”) and do a focused study sprint: skeleton + skin + gait.
    • Summarize what you’ve learned in a single page of notes.
  • Per Project
    • Create or refine a mini‑library just for that world’s fauna.
    • Save it in a shared space for the rest of the team.

10.2 Ethical Growth

As your skills and access grow:

  • Stay curious but critical about where reference comes from.
  • Seek out sources that align with animal welfare, legal standards, and respect for the work of scientists, photographers, and other artists.

Your taxonomy‑based library isn’t just a stash of cool pictures; it’s a long‑term investment in your craft and your integrity.

11. Bringing It All Together

When you build creature designs from a foundation of skeletons, skins, and gaits, organized and understood through taxonomy, you gain a powerful edge:

  • Your creatures feel grounded, no matter how fantastical.
  • Your collaboration with Animation, Rigging, Tech Art, and other teams becomes smoother.
  • Your personal style gains depth, because your stylization choices are anchored in real structure and motion.

Field sketching, museum visits, and scan‑based workflows all become more than isolated activities—they become deliberate ways of feeding your taxonomy‑based visual library. And when you treat that library ethically and respectfully, you’re not just designing cool monsters; you’re participating in a long tradition of artists learning from the living (and once‑living) world.

So the next time you sit down to design a creature, don’t just ask, “What looks cool?” Ask:

What family does this belong to?
How does it move, and why?
What story do its skeleton, skin, and gait tell together?

That’s where a truly powerful creature design practice begins.