I never studied a spine, and I never made any kind of model like this before. It’s quite difficult to discover what it looks like just looking at fossils. They are so different.
I had no idea how to start, so I made a sketch. A three-dimensional sketch. Anything that looks like a spine would work. So I got some foam, and made some cilinders, added some spikes and connected them together with some insulation rubber in between. Since I am going to cover it with skin and muscles, I thought, nobody is going to see it anyway.
This is the result.