Polyptychoceras is an extinct genus of ammonites from the Late Cretaceous of Japan. All these ammonites are found in Hokkaido island in Yubari prefecture, Obira or Mikasa.
These are heteromorph ammonites, rare and hard to find.
All these fossils are found from paleontologist Gianpaolo Di Silvestro.
Upper Yezo Group
Polyptychoceras yubarense Hokkaido ammonite cretaceous
size: 17 cm ammonite
restoration: check scheme...just first curl with some color on broken part
matrix is original from nodule
preparator: Di Silvestro Gianpaolo and Alex Zagar.