 Apoderoceras

Apoderoceras is an extinct genus of cephalopod belonging to the Ammonite subclass.The International Commission on Stratigraphy (ICS) has assigned the First Appearance Datum of genus "Apoderocerasas" and of "Bifericeras donovani" the defining biological marker for the start of the Pliensbachian Stage of the Jurassic, 190.8 ± 1.0 million years ago.