Evolution took a winding path with the nautilus. They curled, over generations, into a spiral.
In order, we’re looking at: Orthoceras, Cyrtoceras, Gyroceras, and Nautilus.
This modernist/pop-art figure came from the 1970s, a book called simply Cephalopoda by Adolf Naef, which I found in the Biodiversity Heritage Library.
Nautiloids are groovy.