Speetoniceras sp.
Speetoniceras
This is a rare specimen among polished ammonite cross-sections. The chambers are filled with pale yellow calcite. Specimens replaced with yellow calcite are also seen in ammonites from Madagascar and Timor, but this specific coloration is rare.
Furthermore, it is very rare to find a 30 cm diameter specimen with such densely replaced internals.
A Speetoniceras from the Early Cretaceous of Russia. This is a cut, pair specimen.
