I never knew dune existed until the first movie then I got two of the graphic novels and watched some you tube videos and the universe and it’s amazing. The one thing that is odd is no aliens haha
Discussion
The navigators are pretty close to aliens, but you're absolutely right.
In the house trilogy prequel the Bene Tleilax are pretty alienish, though very humanoid.
I didn't realize Dune was like book 7 once the others had filled in some holes until just a few months ago.