Anatomical studies: how can you transform into your fursona?

Becoming your fursona or species identity requires drastic anatomical changes. We have a few broad ideas for implementing these transformations. But first, it’s important to describe what the objectives of those transformations are. Here, we’ll take a few of these transformation objectives, taking as an example becoming an anthro wolf or dragon. We’ll analyze their implications in anatomy and physiology, and distill specific changes in morphology into separable research questions. Please note these important points:

(1) These frameworks will help guide our research efforts, but are not set in stone.
(2) This analysis is not intended to be infallible. It’s just supposed to get the ball rolling.
(3) Some anatomical areas will be easier or more difficult than others. If some areas are particularly easy or difficult, we may re-prioritize their research to maximize the rate of overall progress.
(4) This guidance document is not intended to be comprehensive or final. It is mainly intended to be a flexible source of inspiration for researchers, whether internal or external.

The below text is an excerpt from our full-length analysis (20 pages) (PDF). If you want to see more details, please give that document a look!

Head morphology

The head contains a sophisticated arrangement of sensory organs and muscles, and it is home to the most complex computational machine in the known universe. Meanwhile, the face is a memorable feature for others during social interactions, and an important window for one’s inner emotions. Finally, verbalization requires precise coordination of the lips, tongue, larynx, and other structures, all with specifically evolved anatomies.

At a glance:

  • Muzzles will require lengthening of, or substitution of, the mandible and maxilla.
  • Additional smaller cranial shape changes will include the orbits, sphenoid bone, zygomatic process, and temporal bone.
  • In species with elevated ears, they may need (a) longer ear canals, (b) dorso-laterally displaced vestibulocochlear organs, or (c) a short closed-loop auditory signal repeater to maintain sound detection by the inner ears.
  • We expect speech will not be negatively impacted, other than modest changes in voice tone due to larger nasal sinuses. Modified lips and tongues will function normally since we preserve the unique musculature controlling their complex humanoid movement.

Research questions:

  • How can we reshape or replace the cranial bones, especially the maxilla and mandible?
  • For species with elevated ears, (a) given longer ear canals, (a1) will auditory quality be preserved, and (a2) how should the ear canals be implemented; or (b) given displaced vestibulocochlear organs, how can we (b1) accomplish this movement of a delicate structure within larger cranial bones, and (b2) lengthen the Eustachian tubes to remain connected?
  • How can we increase the size of certain muscles, such as the tongue and lip muscles, to remain proportional to the muzzle, and ensure they are functional in speech and other processes?
  • What is the safest method to lengthen cranial nerves, including the optic nerves, to accommodate changed facial proportions?

Tail morphology

The pelvic girdle and surrounding areas are complex anatomical structures frequently under heavy, dynamic strains and loads. An anthro’s tail needs to work within this environment, while minimizing interference with the well-evolved anatomy that humans have evolved for bipedal locomotion. We’ve come up with two examples of how functional and aesthetically pleasing tails can be added to a human’s pelvic area, while staying within these constraints (Fig. 4). Sticking to our canine and dragon anthro examples, we’ll propose neuroprosthetic and biological solutions.

At a glance:

  • Tails will require a long, prehensile mass integrated at or near the base of the spine, the coccyx.
  • Additional skeletal changes may include the sacrum and the dorso-medial area of the hips.
  • The ligaments in this area are complex. This complexity can be ignored if we go with neuroprosthetics, but will be challenging if we attempt to fully integrate a biological tail.
  • Some conscious motor control of the tail should be facile. Sensory innervation should also be possible through using existing nearby nerves in the dermatome.

Research questions:

  • How can we best structurally integrate the tail with the body? (a) If biological, how will we reconfigure the sacrum, coccyx, and nearby ligaments? (b) If neuroprosthetic, then (b1) how will we stably integrate it with bone, and (b2) will the neuroprosthetic be sub-dermal, or will it instead provide a full synthetic skin requiring integration with surrounding skin?
  • How can we power tail movement adequately and precisely?
  • How can we best connect the tail for conscious motor control and for sensory innervation?


Human forelimbs are highly dexterous, due to individual control of fingers and an opposable thumb, and even the ability to rotate (supinate and pronate), deviate, flex, and extend the wrist relative to the elbow. Forelimbs are rooted at the shoulder, and the musculature that controls their movement extends as far away from the hands as the chest and the back.

Most anthros won’t need large forelimb modifications, assuming they keep the same number of digits. The aesthetic of forepaws can be accomplished mainly through slight lengthening and widening of the wrist and metacarpals, ‘fattening’ the soft tissue of the digits, and the exchange of nails for claws.

At a glance:

  • The most visible modifications to the forelimbs are expected to be minimal in terms of skeleton and muscle impact. Common changes might include claws, pawpads, and ‘fattening’ the distal soft tissue of digits.
  • Additionally, some changes might include lengthening and widening the wrist and metacarpals, and reduction of the number of digits from 5 to 4.

Research questions:

  • How can we modify or replace nails with claws?
  • How can we add pawpads, or modify existing skin to produce pawpads?
  • How can we safely modify wrist and metacarpal size?
  • How can we safely change the number of digits as desired?


Fursonas most often include changes to hindlimbs, involving claws, possible changes to the number of digits, and sometimes a transition from plantigrade to digitigrade locomotion. Therefore, hindlimbs are an important anatomical target of freedom of form. We’ve drawn up an example of how digitigrade feet might differ from plantigrade feet, in order to help frame specific research questions.

Hindlimbs are anatomically similar to forelimbs. However, they experience greater mechanical strain and load. The proportions of the upper legs, lower legs, feet and toes must be significantly different from human plantigrade proportions, to achieve efficient balance, locomotion and power transfer, and to be aesthetically correct.

At a glance:

  • Some visible modifications, i.e. claws, pawpads, and ‘fattening’ distal soft tissue, will be moderately easy (as in the forelimbs).
  • If digitigrade posture is desired, metatarsal and phalanges will need significant lengthening and strengthening, and the lower and upper leg may need shortened proportionally. This must be accompanied with stronger ligaments and muscles, especially in the foot.
  • Balance while standing bipedally, in a digitigrade posture, should be fine with a sufficiently large load-bearing base (e.g., larger ground-contact area of digits). Humans with bilateral leg prosthetics have great mobility (e.g. Hugh Herr) despite reduced muscle control of their feet and digits.

Research questions:

  • Similar to the forelimbs, how can we modify or replace nails with claws?
  • How can we add pawpads, or modify existing skin to produce pawpads?
  • How can we safely modify ankle and metatarsal size, especially for digitigrade feet?
  • How can we safely change the number of digits as desired?
  • How can we adjust footpaw design for optimal balance?
  • What skeleton and muscle designs will be of sufficient mechanical strength?

Skin, fur, and scales

To fully become a wolf or dragon, the skin must also be changed. As the largest organ in the body, it is the barrier between the exterior and interior, the division between the hostile world of bacteria, dust, foreign objects and potentially dangerous substances, and the protected and controlled environment of our vast numbers of cells. Our most exposed part of the epithelial layers of the body, skin must at once protect from thermal extremes, retain and deflect water (but also release sweat), and if damaged, it must be able to repair itself. Transformed individuals may want skin coated in thick fur, feathers or scales, with potential benefits to insulation, flight capability enhancement, and armor. Color patterns can be displayed in skin, fur, feathers, and scales, allowing a form of self-expressive creativity for the transformed individual.

At a glance:

  • Human skin already has many of the necessary cell types and pores to grow fur, feathers or scales.
  • Patterns and pigmentation are controlled by processes initiated during embryonic development. It might be possible to mimic these processes, or to create artificial methods to ‘draw’ fur, scale or feather patterns and colors onto the body.
  • Whether scales, feathers or hairs/fur grow, is a matter of which types of keratin structures are produced in what relative quantities.
  • Genetic editing, pharmacological or surgical options may be possible.

Research questions:

  • If we use a neuroprosthetic containing synthetic skin, it will need to blend smoothly into nearby biological skin. What sorts of micro-structure and chemistry will be needed to guarantee a strong, sterile, and seamless transition between natural and synthetic skin?
  • Thermal considerations: how can we ensure someone with fur or feathers won’t overheat? Will sweat glands be appropriate, and sufficient?
  • How can we engineer custom pigmentation patterns for skin, fur, feathers, scales, etc?