This base is remixed from https://www.thingiverse.com/thing:6292817 by Junolupus 

I've just made two pieces out of it, to print the footprint independent of the rest of the base. For example to use a different color and/or to use a much higher resolution on the footprint in opposite of the rest of the base.

After printing I also saw the need for a new rod, because somehow the hole was about a milimeter or so smaller than the one of the original T-Rex base. 

Print settings:

• Base:
  • Layer height: 0.20
  • No support needed
  • Brim: Mouse ears recommended (or based on your experience with warping on your printer :)
• Footprint:
  • IMPORTANT: Resize it down a little bit in x-y direction to match your needs for tolerance!!! I tried no tolerance with my calibrated filament profiles and it worked but it really depends. I suggest 0.1-0.2mm smaller to be sure. If you use different material please be aware of different shrinkage too.
  • Layer height: 0.08 (or as good as you want and can :)
  • No support needed
  • No brim needed
• New Rod:
  • Printable lying flat
  • Layer height: ≤ 0.20
  • No support needed
  • Brim: Mouse ears recommended

When printed just place the foot print in the base. There should be no need for glue.

Hint: Maybe I will tinker the base to match the original rod later, but this needs more effort because converting the base before splitting it into two peaces was simply to much (triangles) for the CAD tools (Fusion 360, FreeCAD) and it took forever, so I finally used MS 3D Builder (want to try something new beside MeshMixer for STL) for the first time to work directly on the STL file. If somebody knows a good and easy tool for STL to step conversion, please write me a comment - or I need to learn Blender for this kind of modifications in the future :)