Believe it or not, the diminutive but rough dwarf is the closest of all the humanoids to be biologically realistic. How?
Let's look up Homo neandertalensis, the stereotypical caveman, in comparison with modern man:
My proposal is that the dwarf's skeletal design be identical to the neandertal's, only compressed in a smaller body--average height, 4'0".
However, certain anatomical differences between dwarves and neandertals are those I propose on all mythological humanoids:
- Tetrachromacy--possession of a fourth color receptor, allowing the dwarf to see colors beyond the visible spectrum.
- Chest--the lungs taking up 15% of the overall body volume rather than the typical mammalian 7%, and a heart so large that if they were human, they'd be diagnosed with cardiomegaly.
However, there is one other difference exclusive to both dwarves and elves--the tapetum lucidum, a tissue behind the retina that reflects light, increasing light availability to the photoreceptors though at the risk of detail. (Though if you are a tetrachromat, that might not be a problem.)
Are any of my proposals listed above sound, or have I created some unintentional side effects to the dwarvish body?