Wings and tails

Wings and tails are the anatomical aspects I really wanted to tackle when I set up this blog. I'll make them more of a focus this year. All too often they are just added as after thoughts rather than being physically useful!

Aesthetics tails and wings that really don't do much!

Tails

Something that's puzzled me for quite a while now is how does a tail work on a biped. Lets take for arguments sake that we are retaining this feature even in some vestigial form. The bones that form the caudal vertebrae of any tail are of course that tiny group of coccyx bones in a human. Far from being just a human vestigial tail, the coccyx is the site for attachment for many important pelvic floor muscles including the muscles of the genitals. How then, could we keep both the functionality of the pelvic floor needed in bipeds to help keep everything 'in' as well as functioning as a birth canal, and the aesthetics of an animal tail. Would caudal bones diverge from the sacrum, or could the sacrum be formed to function like that of the coccyx?

A few sketched ideas on how the pelvic floor could exist in a biped with a tail.