primitives are primitives... ie: cube, sphere, cylinder, torus, plane. 

what else do you need? a teapot? a Bryce dolphin? :D

if you want more complex objects they are no longer 'primitives'.  but there is nothing stopping you from importing whatever free 3D meshes you want into your Poser/Props/Primitives folder and then using them. 

 

BB: nice job with the primitives, you have way more patience than i do :)