I've been spending a lot of time developing aliens for a comic I'm working on, in the skeletal structure department I've run into a bit of a roadblock, how to design a spine for a species that is kind of humanoid, but weighs several hundred pounds more. The spine also needs to be transferable to members of the same species that are over 30 feet tall, living in a somewhat reduced gravity.
My current ideas are; making the spine segments wider, thus providing more support, and adding muscles to reduce stress; adding a secondary spine, so instead of having a single spine in the middle of their back, they have two spines running in sideways arcs up their back (this wouldn't be much of a problem as far as making the torso wide, they already have very broad shoulders and such); lastly, I am thinking of removing the spine and replacing it with something that would resemble an oobleck spine, so it is soft and malleable (which would negate the problem of destroying the back over time as it would be a flexible tube-like organ), but then during times of combat there is a system of muscles that squeezes the spine and causes it to harden.
Are any of these feasible or useful in any way?
edit: Giraffe spines have the same number of vertebrae as a human neck, but they are far larger, and seem to lock together like puzzle pieces. could using less, larger vertebrae be helpful in this situation? I imagine it would make the spine stronger, but less flexible.