Hypoxynoticeras
Hypoxynoticeras is an extinct genus of lower Jurassic ammonite that lived during Jamesoni zone of lower Pliensbachian. Animals belonging to this genus had small platycone shells, of which umbilicus made 25–30% of diameter. Keel was strong and ventrolateral shoulders were prominent. It is possible, that it was just a microconch, or juvenile of Radstockiceras.