These are 3D print ready STL and OBJ files. No non-manifolds. The skull is simplified to make it more easy to print, i.e. no sphenoid bone or small cavities. The skull is hollowed, starting from foramen magnum, to make it easier for resin printers.
Please note, that .stl file does not incorporate the scale units in it. I have made the models on the .zip file to be ready to be printed on a Anycubic Photos S printer, so if you open the .stl file with blender for example, make sure to change the scale to mm. At the moment it uses meter unit, which scales as millimeters in the .stl file and uses that when opened in slicer.
The models are created with blender. The level of detail has been created with the intention of 3D printing in mind and every vertebrae bone and disc have been individually sculpted. The design is meant to be assembled, and it has fitting slots in the discs and vertebrae. That is why the discs look peculiar on their own. They are meant to be printed as a part of the spine assembly. Some of the vertebrae also have concave slots at surface of joint areas to allow them to fit together nicely when printed separately. There is also a separate file with the whole spine and pelvis as a one unit if you want to print it as a whole.
3D print files:
Each vertebrae and disc as their own file
Pelvis spine and discs as a single unit