''Agassiceras'' is a Lower Jurassic

ammonite Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...

from the

Sinemurian In the geologic timescale, the Sinemurian is an age and stage in the Early or Lower Jurassic Epoch or Series. It spans the time between 199.3 ± 2 Ma and 190.8 ± 1.5 Ma (million years ago). The Sinemurian is preceded by the Hettangian and is ...

stage in

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

. ''Agassiceras'' belongs to the psiloceratacean family, Arietitidae, and is characterized by being compressed with a sharp venter and feeble straight ribs that may bifurcate near the umbilical edge.

References

*Arkell et al., 1957. Mesozoic Ammonoidea.

Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology'' (or ''TIP'') published by the Geological Society of America and the University of Kansas Press, is a definitive multi-authored work of some 50 volumes, written by more than 300 paleontologists, and co ...

. Part L. Ammonoidea. Geological Society of America and Univ. of Kansas press. {{Taxonbar, from=Q4691428 Early Jurassic ammonites of Europe Arietitidae Ammonitida genera