Wikipedia
Pseudoaspidoceras
Pseudoaspidoceras is an extinct genus of ammonites in the family Acanthoceratidae.
These cephalopods lived during the Turonian stage of the Upper Cretaceous, between 93.5 ± 0.8 Ma and 89.3 ± 1 Ma (million years ago). Their shells reached a diameter of 90-120 mm and had ornate ribs.