Consider that the number of "fingers" and "toes" for this alien will impact it's culture. Most humans use a base 10 number system because we have ten fingers, it's obvious. An eight fingered alien would use octal (base 8) and six finger hex (base 6).
For your three legged alien, consider tri-lateral symmetry. Or have the third leg be smaller and used for balance. They don't need chairs because they just "sit" on leg #3.
I had a drider character in an RP who did this (okay she was a whip-scorpion from the waist down but I'll use the common term). For each scene, I stopped for a sec to consider how a person with 8 legs and a large lower body would move around. She was also an ice queen
due to her curse/mutation.
So she would push chairs out of the way (since she couldn't use them). She'd "sit" on her legs to get on the same level as a person she was talking to if she was friendly. Or she'd lower her back legs and push up with her forelegs to tower over someone (and to make use of her steel grey eyes
and goth look). She'd even use her forelegs like a second pair of hands if she was sitting, since her other legs could take the weight.
On the subject of feet: the human foot is made to take several tons
of force from walking. Digitigrade
for an otherness, but lets get real. That's a lot of force to put on distal and intermediate phalanges. Apes had toes spread far apart for gripping branches and as a result of finger and toes spread far apart we developed tools over time. They could use one of their legs as a third hand when they are sitting or standing still. And remember Pronation
. I twisted my ankle once, you miss the normal movement of your foot when it's gone believe me. Are your alien flat-footed or do they have arching soles?
It's not the direction of evolution, but it helped.
tl;dr - the takeaway would be to have the aliens with 3-legs have either:
- back leg with fused toes like a tail, they can sit on it like a chair, their spine and hind leg are in perfect alignment.
- their feet kinda-sort look like human feet from a distance, but only in that they were descendants of a primate-like critter.
- consider tri-lateral symmetry. Their body has three sides.
- remember the impact their body and anatomy has on their culture. Would a three-legged (and possible 3-sided) alien see us two-legs (2-sided) "huu-maans" as weird?
- Comparative foot morphology via the other wiki
edited 22nd Feb '13 7:22:32 PM by TairaMai